You can try asking State Bank of India and some of the large private sector Indian banks like HDFC and ICICI Bank. Googling will easily get you their sites and some links or emails via which to contact them.

I recently checked with my bank about paying vendors outside India via online methods, but that was for personal use, like buying small consumer items, not as a company. They did say it was possible. But if your clients in India are companies, you will have to check - the rules (and available methods of payment) are likely to be different for companies than for individuals.