I want eCommerce solution to my application where money can be transfer from buyer to seller

Workflow:
Buyer can purchase a product from my application by using various options like PayPal or CreditCard.

The money can be directly credited to the seller.

Is there any built in solution in Rails, Suggest me.

No built in solution shipped with Rails. However, you may want to check out the Active Merchant gem, which supports many payment gateways to include PayPal.