No 

 Yes- within 12 months from the date of first filing of the priority application. 

Worldwide

required. 

1. A Power of Attorney, simply signed. Attested by two witness 
2. One copy of the English specification and claims.
3. One set of the drawings relating to the invention, if any.
4. An abstract of the invention 
5. A certified copy of the application giving the filing date, number and country if the application is to be filed with a priority claim.

4 months 

20 years starting from the filing date. 

If the patent is not exploited within 3 years from the date of grant, it will be   subject to compulsory licensing. (or working is stopped for 2 consecutive years) 

Annuities are to be paid starting from the fifth year of the patent term and are paid in advance at the beginning of the fourth year.