Mobbed by cheering crowds, former prime minister Indira Gandhi was released tonight after a week in a jail and said she would run again for a seat in Parliament.

Gandhi, expelled from the lower house Dec. 19 and imprisoned for breach of privilege and contempt of Parliament for blocking a probe of her son, Sanjay's, activities while prime minister, told a pess confrence at her home: "I will certainly contest again."

She described her week behind bars as a rest cure and said although "it was politically motivated," she was not bitter about her imprisonment, which ignited nationwide demonstrations that killed at least 14 persons. An airliner also was hijacked by pro-Gandhi supporters.

Gandhi, 61, looking tired but determined, said of Prime Minister Morarji Desai's ruling Janata Party: "It is not a question of whether it will stay in power or not, but whether it is governing at all."

Her words coincided with fresh trouble for the bitterly divided government as Information Minister LaKrishan Advani resigned in protest over the way Parliament had handled demands for an inquiry into corruption charges against Desai's son Kanti.

Gandhi, the first former premier of India to be jailed by Parliament, had been ordered to stay in prison until the present session ended. It would up Saturday but was not formally adjourned until today.

As the crowd cheered and danced outside her home, Gandhi said she had expected the wave of protests after her arrest but did not support the violence. Of the airliner hijacking, she said it was "only" a prank.