e-Comm only carries Paypal and Authorize.net gateways by default, otherwise, you'll need a gateway add-on from the marketplace. If you don't see an add-on for your gateway, you can write one (or hire someone to do so) or change your payment processor.

What payment processor are you using?

thank you so much for replying.
My gateway is with 5/3 bank. So your are saying that if I want to continue to use 5/3 bank then I need to purchase an add on from the market place that will allow me to connect my web page to my bank.

That's correct. I don't see an add-on for 5/3 though.

If I use say pay pal, then how will I get the money for purchases?

Paypal is included by default with the eComm module. You can go through the setup from within your Concrete5 site and Paypal.

As you collect payments using Paypal, you simply transfer the money on Paypal's site.

That being said, I wouldn't use Paypal unless I was sure I could money out on a daily basis. If they ever suspend your account, it can take months to even find out why, much less get it released.

If you're based in the US or Canada, we're a Beanstream Channel Partner. If you sign up through us, I'll grant you a couple of free licences to the gateway we created. PM for details if you're interested.