Marrying an illegal immigrant in the UK

Hello sir i've a girlfriend in US she is american citizen and im a illegal immigrant in UK i want to be a marry with her bu she dont want to go to india she just dont like india there is any possibility in which my girlfriend come to london and apply for my american visa im OK to go to india for a visa but she was not ok so tell me if there is anything to do in my case.
Thank you

Are you asking about applying for a USA visa, or marrying your girlfriend in the UK

I am not sure if you can marry as you need home office permission to get married and since you're ilegal I think home office might detain you at some point. I'll be very surprised if home office grants you permission.
If you get married, she can go back to USA and you go back to India and apply your visa as you can't apply from UK as you need your passport (if your previous visa has been refused, home office might have kept your passport) and need proof of residence if it's not your birth country. There might be a way around this, it's better if you speak to a good solicitor.

Your American girlfriend would also require a Marriage Visitor visa and I very much doubt that she will be issued one in the circumstances. In addition to your own immigration issues, she will be unable to marry in the UK while here as a normal visitor.

Have you met in person