Hello,
I have experience with PHP and MySQL.
As from your request, you are using ResellerClub's Supersite to selling Services, and want to add payumoney as payment gateway on this.
I already worked in past with payumoney to integrate with Core-PHP sites. and they alredy did the documentation to how to add another gateway to your account.
So discuss me in details so I can do work.
From your side I need working Reseller club account.
Arjun