First, you need to talk to your girlfriend calmly and try to change her mind. She needs to understand that even if she would succeed in keeping you without doing a breakup but later on, no one will be happy in that relationship. Secondly, she doesn’t have any right to upload anyone’s intimate’s videos online without their consent. Every citizen has the right to privacy under article 21: Right to life.
And if she uploads the video, then you can file a case against them under cyber law. Using someone’s picture/video without their permission is an offense under cyber law. Under cyber law, you can file a complaint in the cyber cell police station against any person who is doing this crime.
And also you can file a defamation case against your girlfriend.