Let's see
Ashok's suicide -- how did he bring that can of gas/petrol/oil/kerosine to the event ? How did he pass through security? We saw 20-30 security guards during individual introductions. Where are they all?
Power/electricity -- Shivaay is too busy arresting Anika , and no one else gave second thought to how/ why they lost the power in the first place?
Car blast. -- happened right in their house / in front of the house. don't they have garages? Why his car is parked out side? Talked about tightening the security, but never about how/who did it and why?
Poison -- passed into Shivaay's body by touching. This one was witnessed by Om
Blood bottle -- something was injected into it.
Ashok's wife -- when she admitted that she is the one did all these to take revenge on her husband's death. No one wondered how one common man/woman can do all these. Only one time these events rewinded in Shivaay's mind and didn't give any thought to it after that. Happily went for a coffee without security and bought a car on the street. And our hero chasing the girl for a chip.
Aunt -- I think she gave an explanation how she ended up in the hospital and how she rescued her nephew. But anyone wondered about the timing of her entry knowing her past?
Blood transfusion -- mother of all puzzles . Isn't it blood transfusion happens when you are low in blood level/count? Is Doctor first pumped out the poisoned blood from Shivaay and then performed blood transfusion? Do I need to be a doctor to understand this mystery?
What is the recovery time after blood transfusion especially when you have some heart condition?