get selected index of checkbox inside gridview while saving

I have a gridview in which there are many checkboxes including rows and columns. Here is a preview of the gridview below

and the aspx of the code is below

<cc1:Grid ID="GrdWorkingCompany" runat="server" OnRowDataBound="GrdWorkingCompany_RowDataBound"
                                    EnableTypeValidation="true" CallbackMode="true" Serialize="true" ShowFooter="false"
                                    AutoGenerateColumns="false" AllowAddingRecords="true" AllowSorting="false" Width="100%"
                                    FolderStyle="~/Styles/Grid/style_12" PageSize="18">
                                    <Columns>
                                        <cc1:Column ID="Sr_No" ReadOnly="true" DataField="SrNo" HeaderText="Sr.No." Width="50px">
                                        </cc1:Column>
                                        <cc1:Column ID="Points" ReadOnly="true" DataField="Points" HeaderText="Points" runat="server"
                                            Width="300px">
                                        </cc1:Column>
                                        <cc1:Column ID="chkPoor" ReadOnly="true" DataField="Rating1" HeaderText="Poor" Width="110px"
                                            TemplateId="tpltPoor">
                                        </cc1:Column>
                                        <cc1:Column ID="chkSatisfactory" DataField="Rating2" HeaderText="Satisfactory" ReadOnly="true"
                                            Width="110px" TemplateId="tpltSatisfactory">
                                        </cc1:Column>
                                        <cc1:Column ID="chkGood" ReadOnly="true" HeaderText="Good" DataField="Rating3" Width="110px"
                                            TemplateId="tpltGood">
                                        </cc1:Column>
                                        <cc1:Column ID="chkExcellent" HeaderText="Excellent" DataField="Rating4" Width="110px"
                                            ReadOnly="true" TemplateId="tpltEx1">
                                        </cc1:Column>
                                    </Columns>
                                    <TemplateSettings GroupHeaderTemplateId="GroupTemplate" />
                                    <Templates>
                                        <cc1:GridTemplate runat="server" ID="GridTemplate2">
                                            <Template>
                                                <%# Container.Column.HeaderText %>
                                                : <i>
                                                    <%# Container.Value %></i> (<%# Container.Group.PageRecordsCount %><%# Container.Group.PageRecordsCount > 1 ? "records" : "record" %>)
                                            </Template>
                                        </cc1:GridTemplate>
                                    </Templates>
                                    <Templates>
                                        <cc1:GridTemplate ID="tpltPoor">
                                            <Template>
                                                <input type="checkbox" id="chkA1<%# (Container.RecordIndex)%>" name="chkAC1" style="width: 17px;
                                                    height: 17px;" value="<%# (Container.RecordIndex)%>" onclick="AppoveCheckA(this)" /></Template>
                                        </cc1:GridTemplate>
                                        <cc1:GridTemplate ID="tpltSatisfactory">
                                            <Template>
                                                <input type="checkbox" id="chkA2<%# (Container.RecordIndex)%>" name="chkAC2" style="width: 17px;
                                                    height: 17px;" value="<%# (Container.RecordIndex)%>" onclick="AppoveCheckA(this)" /></Template>
                                        </cc1:GridTemplate>
                                        <cc1:GridTemplate ID="tpltGood">
                                            <Template>
                                                <input type="checkbox" id="chkA3<%# (Container.RecordIndex)%>" name="chkAC3" style="width: 17px;
                                                    height: 17px;" value="<%# (Container.RecordIndex)%>" onclick="AppoveCheckA(this)" /></Template>
                                        </cc1:GridTemplate>
                                        <cc1:GridTemplate ID="tpltEx1">
                                            <Template>
                                                <input type="checkbox" id="chkA4<%# (Container.RecordIndex)%>" name="chkAC4" style="width: 17px;
                                                    height: 17px;" value="<%# (Container.RecordIndex)%>" onclick="AppoveCheckA(this)" /></Template>
                                        </cc1:GridTemplate>
                                    </Templates>
                                </cc1:Grid>

So, Now what I want is

I want to save the checked checkbox value into the database table on button click

What I tried is below:-

/*1st Grid GrdWorkingCompany saving code*/

        string[] arrS = hidRateA.Value.Split(new char[] { ',' });


        if (arrS.Length != 18)
        {
            arrS = "0,0,0,0".Split(new char[] { ',' });
        }


        for (int intCount = 0; intCount < arrS.Length; intCount++)
        {
            xw.WriteStartElement("p_emp_Company_Rating");
            xw.WriteElementString("CREATED_BY", Hid_userid.Value);
            xw.WriteElementString("CREATION_DATE", System.DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss"));
            xw.WriteElementString("LAST_UPDATE_DATE", System.DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss"));
            xw.WriteElementString("LAST_UPDATED_BY", Hid_userid.Value);
            xw.WriteElementString("Sr_no", (intCount + 1).ToString());
            xw.WriteElementString("Points", "");
            for (int i = 1; i < 5; i++)
            {
                if (arrS[intCount] == i.ToString() && arrS[intCount] != "0")
                {
                    xw.WriteElementString("Rating" + i.ToString(), "Y");
                }
                else
                {
                    xw.WriteElementString("Rating" + i.ToString(), "N");
                }
            }
            xw.WriteElementString("DELETE_FLAG", "N");
            xw.WriteEndElement();
        }

But it is not getting saved.

If there is any other way round to achieve this kindly help me out.