His real name is Rajeev Bajwa as in first epi the previous Gurinder who played his mother called him Rajeev. He introduce himself to Pari & family as Rajeev even Rakesh knows him as Rajeev. When he met Neeti for marriage in Barnala she rejected him even w/o hearing his name. His real name is Rajeev Bajwa,Sanju is his nickname that being called at home and Mehra is his maternal side surname so he married Pari with his real name Rajeev Bajwa & change his name to Sanju Mehra to woo Neeti at the same so that Pari & her family cannot find him he did mention to Pari when she expose him he changed his name so that Pari & her family won't be able to find him and he can continue his love story with Neeti
When Rajeev was in Barnala he wanted to go out of pind as he wants a mordern lifestyle and lofe partner village is not his place. He was architect by profession in pind but his goals were high he wanted to work in a big firm in chandigarh & that job he got it after his marriage with Pari. He lied to Pari & her family,left her alone and just vanish no calls nothing from him while she was waiting for him. He changed his name to Sanju Mehra & got the job. I wonder how he got the job as Sanju Mehra when his actual name is Rajeev Bajwa. Its a fraud actually and that dumb company did not even check his background