Here, I doubt if there's a scope for a bridal mix up as everyone seems to be aware of the existence of the two brides.
So, either there will be no marriage or Ragna will tie the knot...unless, Kamla, Neetu and Pakhi together browbeat poor Kalpi into giving up Raghav...in which case, I think , he is certainly going to have a say in the matter. There's too little time or opportunity for him to discover his mother's existence and find out the truth about her disappearance for him to go back to revenge mode and marry Pakhi to get even.
So, in short, EMA will surprise us yet again and have Ragna marry after all and move on to Gauri's discovery and its sundry resolutions..