Hi Vikash,
Currently there is a possibility to create a template which creates work item and the children. Here is the procedure how to do it in web ui:
1. Create work item from which you want to create a template
2. Add a child work item to this work item
3. Run a query which returns the parent work item as a result
4. Select work item created in 2
5. Click Create Work Item Template button
6. From the menu selecting work item select workitems created in 2 and 3

There is no possibility to create a template pointing always to the same work item.

Please let us know if my answer helped.