There are so many- so many!- possibilities. I don't even now where to begin.
I think it's safe to assume that this wedding will be called off. I'm okay with that. More than okay actually since I hated the idea of Naku replacing Supriya on her wedding from the start. Let the man fall with the right girl and then let them have a proper wedding.
But now to the bomb blast. There are so many things that could happen and I have no idea where the writers are going to take the story.
There are witnesses on the scene and- as I don't think, Kala did clear the place- most probably evidence of the blast. I'm not sure how many of the witnesses are bought by Kala. Some maybe. But even if it that is the case, there'll be surely some that were there "by accident" and would tell Dutta- who will surely want be there to investigate/ see the scene with his own eyes- that Naku was a total mess so to speak. They could tell him how she was actually totally taken by surprise and tried to run to the car after the blast.
There is also the guy with the coconut water stall. I think, most probaly, if Naku gets the chance to tell the whole story, she will tell Dutta about everything him. How he asked for her during the ceremony even though she had never seen/ met him before, nor made any calls or whatever. But his sisters, his mother, Supriyas mother ... they've seen him too, of course, and only God knows what they will tell him about the incident.
Ravi dropped the remote. That alone doesn't really prove anything other than the bomb. But since the camera zoomed on it, we'll have to wait and see what the creatives have planned to do about the thing, I guess.
And there is the jewellery. Now that is really a proof. The question is, will it be found? And if yes, will Dutta get to know about?
Anyways, don't get me started about the stupid letter. I have no idea why it is needed.