Why Tine didn't Cameback!!!

I think Tina aka Mukti/Devki didn't came back because of Manoj, because there are best friends and maybe she felt like she can't do the show without manoj as there jodi was well liked and audience may not like Tina/Vikas jodi.

also her role was reduce after Manoj left

I think this is the reason Tina didn't came back to Kasauti...