Which Indian batsman played longest innings in test cricket?

In a test match against Pakistan, Indian Batsman Rahul Dravid played longest innings ever played by an Indian in Test cricket by staying 740 minutes in crease with a score of 270. Previously Sunil Gavaskar played longest innings by staying in crease for 708 minutes in a test match against England.

This is also third slowest double hundred by an Indian.  Dravid took 647 minutes to complete his double hundred. Only Navjot Singh Sidhu and Anshuman Gaekwad have taken longer to complete their double hundreds.