Is it possible to use same network on wireless router

Change the IP address of the wireless router to be something in the 192.168.2.0 range but outside of the DHCP scope, disable DHCP and connect the network cable to a LAN port and not the WAN port. If you need the WAN port you need 3rd party firmware like DD-WRT.

this is the router we are having
http://www.aztech.com/prod_3g_hw550.html
if i removed cable from WAN port , then how can i get internet for laptops with wireless

Then just reverse it and make the changes to the wired router.

[modem](lan)<--wire-->(wan)[router #1 (192.168.1.1)](lan)<--wire-->(lan)[router #2 (192.168.1.2)]

All clients of both routers have access to each other and the Internet because they all share the same network, they're merely switched. The only routing that takes place is from router #1 to the Internet via its WAN port.

That’s why you don’t use the WAN port of router #2, otherwise those clients WOULD be routed between routers, and hence the need for a different network, clients of router #1 would be denied access to clients of router #2 by its firewall, etc.

The only caveat is that because router #1 and router #2 are on the same network, and you never want more that one DHCP server per network, you need to disable router #2’s DHCP server.