After a discussion with tei fc admin i was directed to look at an webiste on the new movie sid is apparently leaving the show for called masti in bangkok. This is the website:
http://www.bollywoodhungama.com/moviemicro/cast/id/576460/Masti%20in%20Bangkok
The confusion is because i saw this poster a few months back before tei started and this is the same poster but when i saw it at that time it was originally called bang bang bangkok, so the name has been changed as well as the release date as this movie was meant to release in 2013 originally so it is an old movie sid already shot for but is being released later this year instead of its original release date. I even saw old photos online of sid shooting for this movie with the cast members of the movie so the movie has already been shot for.
When i pointed this out some people said masti in bangkok is probably a sequel then to bang bang in bangkok but the same exact poster but with altered title indicates the movie has undergone a name change as that happens at times and plus movies can sometimes release really late owing to problems such as shahid kapoor and kareena's milenge milenge and ajay-sanjay-manisha's mehbooba. So this means this is not a new movie but an old movie of sid that had a postponed release.
So why would sid leave the show for a movie that he already shot for and was released late? He wouldn't leave the show for a release of a movie plus sid said it is a big project he couldn't turn down, but this doesn't even seem like that big of a project unfortunately for him to leave tei. Plus TOI said he was leaving for a better project he got on the small screen, meaning another show.
The fact is sid has been very vague in the statement he has given and it is hard to indicate whether he is leaving for a movie or another tv show. I'm still waiting for an official confirmation from sid that will indicate he has made his decision to leave and why he is leaving.