NEW DELHI (Reuters) - Bollywood actor Sanjay Dutt, jailed for six years for receiving guns from gangsters involved in India's worst bombing in 1993, challenged his conviction in the Supreme Court on Tuesday and sought bail.

Legal experts said it could still be days before the petition is listed in court for hearing, but in India celebrity cases are often expedited.

Dutt, 48, began serving his six years "rigorous imprisonment" last week in a prison in western India - less the 16 months he served while awaiting trial over the bomb attacks that killed 257 people in Mumbai in 1993.

He was cleared of conspiracy in the bombings.

"We have filed a petition seeking bail for Sanjay Dutt," the actor's lawyer Satish Maneshinde said. "We are also challenging his conviction."

Dutt's appeal said his conviction by a special anti-terrorism court was based on his confession that he had later retracted.

"A retracted confession is a weak piece of evidence," the petition said, arguing that the conviction should also be overturned because no arms or ammunition were ever recovered from Dutt or his home.

The petition, which said Dutt should be granted bail because he was "not likely to commit any offence while on bail", urged the court to award him some form of punishment other than jail.

Dutt's sentencing has evoked a mixed response from Indians with some hailing the verdict and others calling it too harsh.

But the Hindi-language film industry has stood behind the muscular actor, who is seen by most as an impulsive man but not dangerous.