This Code snippet will help you to disable the link button link within rad grid based on some condition

AspX Page

<telerik:RadGrid ID="radgrdValuesetParameter" runat="server" AutoGenerateColumns="false"

GridLines="None" BorderWidth="0" AllowSorting="true" AllowMultiRowSelection="false"

PageSize="20" AllowPaging="true" PagerStyle-Mode="NextPrev" PagerStyle-AlwaysVisible="true"

OnPageIndexChanged="radgrdValuesetParameter_PageIndexChanged"

OnItemCommand="radgrdValuesetParameter_OnItemCommand"

onitemcreated="radgrdValuesetParameter_ItemCreated">

<MasterTableView DataKeyNames="ID">

<Columns>

<telerik:GridTemplateColumn UniqueName="TemplateColumn" HeaderText="#">

<ItemTemplate>

<asp:Label ID="numberLabel" runat="server" />

<%# Container.DataSetIndex+1 %>

</ItemTemplate>

</telerik:GridTemplateColumn>

<telerik:GridTemplateColumn HeaderText="ValuesetParameterName" UniqueName="ValuesetParameterName">

<ItemTemplate>

<asp:LinkButton ID="lnkEdit" runat="server" CommandName="SomeCommand" Text='<%# Eval("Name") %>'></asp:LinkButton>

</ItemTemplate>

</telerik:GridTemplateColumn>

</ MasterTableView>

</RadGrid>
CS Page

protected void radgrdValuesetParameter_ItemCreated(object sender, GridItemEventArgs e)

{

if (e.Item is GridDataItem)

{

GridDataItem dataItem = e.Item as GridDataItem;

LinkButton lnkbtn = (LinkButton)dataItem.FindControl("lnkEdit");

if (Convert.ToBoolean(Session["IsEditable"]) == false)

{

lnkbtn.Enabled = false;

radbtnAddNew.Visible = false;

}

}

}