If Tulsi is supposed to be back then the possible story line could be:
Remember the lady sitting next to tulsi in truck will be deemed as tulsi who is getting plastic surgery.
Real Tulsi is saved by flying off the falling truck and hitting a soft patch of land.Later saved by a guy who happens to be the son of Karan and nandini.
Thus the team of Nandini, Ganga, Tulsi and son of Nandini and Karan take revenge through Gautami, who will be impersonating the real tulsi.