The SR300 has been selling recently in Intel's online Click store in a 'last chance to buy' sale of the old RealSense models. Unfortunately it is now out of stock.
An alternative would be the Creative BlasterX Senz3D. It is almost identical in design to the SR300, as Creative manufactured the official SR300 for Intel. The BlasterX works fine with RealSense SDK software and uses the same driver files.
Here is the BlasterX's page for India.
This site has a list of Indian retailers who stock Creative products. In Pune, these are:
FORTUNE MARKETING PVT.LTD
201,Second Floor,Nanasaheb Pasalkar Bhavan,
Shivajinagar Court Road,Shivajinagar,
Pune SUPERTRON ELECTRONICS PVT.LTD.
Shri Sadgurukrupa building Opp.
Eisha palace Salisbury Park, (Jain Mandir)