Proof for transfer of unlisted shares

Jigna (Student CA IPC / IPCC) (55 Points)

22 December 2014  
when there is transfer of shares of unlisted company say X which result into LTCG & another tranfer of shraes of unlisted company say Y which result into LTCL. this LTCL of Y is setoff against LTCG of X. Pls let me know procedure to transfer shares of Unlisted Company. and most important is what documents to be given as a proof of transfer of shares of unlisted company when demanded by some one or say Assessing officer ???
Pls revert as soon as possible.