@chamara have you tried using .DefaultValue() in your grid ? This works for me.
Like this?
@(Html.Kendo().Grid(Model)
.Name("grid")
.Columns(columns =>
{
columns.Bound(p => p.UserName);
})
.ToolBar(toolbar => toolbar.Create().Text("Add"))
.Editable(editable => editable.Mode(GridEditMode.PopUp).TemplateName("template"))
.DataSource(dataSource => dataSource
.Ajax()
.Model(model =>
{
model.Id(p => p.ID);
model.Field(f => f.UserName).DefaultValue("+94");
})
.Read(read => read.Action(" ", " "))
.Create(update => update.Action(" ", " "))
.Update(update => update.Action(" ", " "))
.Destroy(update => update.Action(" ", " "))
))
The defaultValue should be visible in your pop up.