Siddharth rose to fame with his performance in the movie Rang De Basanti. He received very good reviews for the manner in which he portrayed the character of Karan. The actor said a lot with his facial expressions even though the dialogues of him were very limited in the movie. After a break of that sort, he went into a hiding of sorts until very recently when his movie Mukhbir was released.

The movie saw him in a completely different avatar. The movie failed to do well at the box office but earned him positive reviews but his performance saw a slide as compared to the previous one. He has managed to keep his career afloat though and is currently doing a movie with Ravi Babu who is a renowned director in the South. Sunkara Madhu Murali along with Ravi Babu is co producing the movie.

His character in the movie somewhat resembles the character of Hrithik Roshan in the movie Lakshya which was directed by Farhan Akhtar. He plays a young spilt brat who is very lazy. With his career heading nowhere he joins the Indian army to prove a point to his family and everyone around. The decision turns to haunt him but eventually he manages to prove his point.

Siddharth in fact was not the first choice to play Karan in RDB. Rakeysh Om Prakash Mehra had gone to Hrithik to play the part but when he turned down the role, as he was very busy at that time the role went to Siddharth who managed to get his career rolling after that movie was released. He is currently trying to get in shape for the movie.