And it is also possible that Munna is addu and Beera is actually the real Munna who is acting like Beera to know about the Bhatnagars to know about their strengths and weaknesses! Beera is the one giving all the info to Munna but I guess he is not able to give the full info..that's why Munna is have so many misunderstandings..
Beera, the guy who burnt his own bike for betraying him, why would he forgive the girl who betrayed him so easily? and I feel there was an intention behind him entering the Vyas house..maybe it was Munna's plan and even that fight between Beera and the Daddaji gang before Mohan gave Beera a job was also fake just to make Mohan believe that Beera is a good person and so that Beera could keep a close watch on the Bhatnagars.