Payment gateways for smaller merchants

CCAvenue
http://www.ccavenue.com/pricing.jsp

PayU (goibibo group):
https://www.payu.in/whypayu

Zaakpay (Started 2 years back) has easier integration kits:
https://www.zaakpay.com/developers/guide

Payzippy (Flipkart)
https://www.payzippy.com/faqs

DirecPay (Times group)
http://www.direcpay.com/direcpay/direcpay-features.jsp

Other than these, individual banks also provide APIs for payment processing. But, there is huge setup time and greater hassles in dealing with them.

Integration is not for the laymen. Some knowledge of basic programming is needed for the basic integration with the APIs exposed by the gateways.