it is the same guy who killed Dr. Amit and Freddy since:
1) he is dressed in black
2) he is expert at backstabbing
he was also seen dragging Freddy's body when Shiv was looking at them in one scene ... Vyom makes perfect sense since he was at Sharanya's house when Dr. Amit called .. and when Freddy called Sharanya, Vyom realized that Sharanya was not in the shower ... in both the cases he must have quickly reached there and did his murders before Sharanya can speak to them.
but he couldn't have killed Ram cause he was possessed by some paranormal being ... possibly Shiv ... even if all the possession was a drama ... even then he couldn't have done it since he was present at the wedding ... so maybe Rajan killed Ram Uncle as he was following him.
Cops are definitely helping Vyom and Bedi family too ... lying about Dr. Amit's character ... whispering something in Vyom's ear so Sharanaya couldn't listen ... stealing knife from Odhni while she was in cops car ... handing out CCTV footage to Bedi family ... and sending Odhni to prison without a trial ... and possibly keeping Shiv's murder all hushed up