Deductible Interest Expenses for Oversees loan

I have a couple of questions about what can be considered as decuctible expenses with relating to Income tax.

The scenario is

- Investment being made in a commercial property in India by an NRI.

- The capital for the purchase of the propery is coming from two sources

     (i) -  From mortgaging another property  (in India) that belongs to the NRI

     (ii) - From loans from oversees banks in the Country of Residence of the NRI

Questions:

 1- Is the int paid on the mortgage in scenario (i) deductible as a valid expense?

 2- Is the int paid on the loans in scenario (ii) deductible as a valid expense?

 3- If the above int exps are deductible, can these losses be carried forward?

 4- If the above int exps/loss can be carried forward, how long can they be c/f ?

 Appreciate your time to respond to my queries.