Thanx Michael Branscomb i tried group of layer
1) At first i picked up a layer from TOC and add it to group layer class and add that grouplayer to mapview it is displayed in TOC successfully.
2)But next time when i want to add another Layer from TOC to the existing group it will show me an error that object already owned.
3)And one more thing can i pick up multiple layer From TOC and add it to the group Of layer?