Kapoor was arrested and taken to the Juhu police station. A case of attempted suicide has been slapped against her, said Pradip Singhdhe, a senior police official.
Earlier, Kapoor had held a news conference, claiming that before Abhishek met Aishwarya Rai, who are to marry Friday, he had dated her with promise of marriage.
She had played a small role in Abhishek-starrer "Dus" and had a dance number with the star.
The actress, with blood dripping from an allegedly slashed wrist, had reached the Bachchan bungalow after midnight Thursday, trying to force her way into the high-security Bachchan home, Jalsa, where pre-nuptial celebrations of the Abhishek-Aishwarya wedding were in full swing.
Sources said she was rushed to a local hospital for treatment. The actress reappeared, apparently drugged, before the Bachchan bungalow Friday, to allege that Abhishek had ditched her. "I tried to slash my wrist last night, unable to bear that Abhishek has ditched me to marry Aishwarya," said the actress, whose left wrist was bandaged, in what was widely seen as a desperate attempt to gain some media publicity. She is reported to be from Lucknow and also has a Kashmiri connection, sources said.