Hi  PRA,
Please refer below sample.
HTML
<div>
    Name :
    <asp:TextBox ID="txtId" runat="server"></asp:TextBox>
    <asp:Button ID="btnSubmit" Text="Submit" runat="server" OnClick="GetId" />
    <asp:Label ID="lblMessage" runat="server" />
</div>
Code
C#
protected void GetId(object sender, EventArgs e)
{
    string[] splitxt = txtId.Text.Split(',');
    string id = "";
    for (int i = 0; i < splitxt.Length; i++)
    {
        id += splitxt[i].Split('-')[1] + ",";
    }
    lblMessage.Text = "Id is :" + id.Remove(id.Length - 1);
}
VB.Net
Protected Sub GetId(ByVal sender As Object, ByVal e As EventArgs)
    Dim splitxt As String() = txtId.Text.Split(","c)
    Dim id As String = ""
    For i As Integer = 0 To splitxt.Length - 1
        id += splitxt(i).Split("-"c)(1) & ","
    Next
    lblMessage.Text = "Id is :" & id.Remove(id.Length - 1)
End Sub
Screenshot
