Nexus 7 is behaving weird

[ceylons]

I purchased this wifi modem from isp last week https://www.acanac.com/hardware/smart-rg-sr360n. My Nexus 7 does not connect to the modem. My Moto X and my laptop are working fine with the modem. My nexus 7 is getting connected to the old router too. I wonder why it is not connecting to my new modem.

[JSB2000]

You might try forcing the Nexus 7 to use a single radio band under the advanced WIFI settings instead of the standard automatic setting.

Also, if you're using bluetooth, try turning it off. Bluetooth and WIFI sometimes interfere with each other. 

[ceylons]

@JSB2000 Nexus 7 got connected when changed the radio band settings (y). Thanks mate! But, why can't I connect it using the normal way? :|

[JSB2000]

@JSB2000 Nexus 7 got connected when changed the radio band settings (y). Thanks mate! But, why can't I connect it using the normal way? :|

You're welcome.  Glad it worked.

My best guess is that the automatic setting affects the sensitivity of the radio on certain frequencies (including the one your router is using).  Overriding it allows the Nexus to "focus" on the specific band in use.