I want to receive SMS in two different phones simultaneously The messages sent to one phone meant for it only should also be received by the other phone. What is the way out?
It's easy. 
You'll need to use an SMS Forwarding software,
I'm not sure if you want it to be visible however... 

If you would like to forward calls, 


Open Dialer   
Open Call Settings in Dialer   
Navigate to, and change the call forwarding number when unanswered.   


If you want to forward SMS, 


Download an SMS Forwarding software  
Enable forwarding of incoming and outgoing sms or just incoming.