How to connect Xbee gateway to xbee ProS3B without xbib dev board?

I want to know how to connect a xbee gateway to a network of xbeePro (900hp), I tried using the same PAN Id on all the modules but the gateway does not find them.

The Xbee Gateway and the 900HP modules are incompatible. They operate on different frequencies.

You will need an X4 gateway with a 900HP module in it if you want a Digi gateway.