I guess, next saturday episode will go like this:
Ritik and shesha will go to mandir to save shivanya, where shiv will encounter the python. Shesha will save her and they will start the pooja. After the success of pooja, shivanya will need some more time to heal completely, so shesha will go back home with ritik. At home everybody will be waiting anxiously for them, when (real) guruma will come and inform them that the naagin is still alive and blah blah blah... then ritik and shesha will return home and things will go on as seen in one of the olv's.
Since it is 3 month anniv, angad, divya and amrita will plan that card prank and shesha will find it excellent opportunity to create rift between ritik and shiv. Then real shivanya will come home and shesha will go back. That night there will be a fight between ritik-shivanya, as seen in yesterday's olv. In the meantime, shailesh and ramya will come home and tell yamini-anky that shivanya is naagin (it might be possible that they saw shesha changing shape). They will call ritik-shivanya down and ritik will protect shivanya.
At this point, I think saturday's episode will end.