Dear Pawan,
The purpose of writing off will determine the impact on IT Depreciation, there can be 2 cases-
1) Entire Block is ceased to exist (due to say fire, etc) & the bock has not been reinstated in the same FY by adding new asset falling in same block -
Depreciation under IT Act will not be allowed..
Further, whether Capital gains will be computed or not will depend upon the fact that u were having insurance cover or not, If u were having insurance then in the year of receipt of claim the wdv less insurance claim will be a short term capital loss&
If u were not having insurance then no deduction or loss will beallowed under Income Tax neither under PGBP nor Capital gains.
2) Entire Block is not ceased to exist or the Block was reinstated by purchasing another asset in the same FY falling in the Block
Follow what brother G.K. has told above...