There were reports claiming that director Mohan Raja's next film would be with STR. However, during a recent conversation with his Twitter followers, Mohan Raja made an important clarification.
 

When asked if his next film would be with STR, as rumoured, the Velaikkaran director replied,  "I hav not decided on my next film yet"

Looks like we will have to wait for some more time to know about his next film.

*tweet is not spell-checked