The film starring actor Vikram was scheduled to release for Pongal next year, which now seems doubtful.
"The makers are spending a lot of time on the special effects and getting the film dubbed in multiple languages. This might push the release date further by a few weeks. Shankar sir is a perfectionist, so he prefers taking his time to produce a satisfying product," a source from the film's unit told IANS.
I is expected to be released in over five languages.
The film which is made on a budget of Rs 100 crore completed the shooting recently, after being on floors for over two years. Nearly 50 per cent of I was shot in China.
The film also features actors Amy Jackson and Upen Patel. Vikram lost nearly about 50 kg for his role in the film.