I'm not going to second guess your attorney, because he's familiar with the facts of your case and has seen the court
papers and conferred with the prosecutor and knows what you're up against. If he tells you that you have no chance of winning at trial, I think you should take that statement pretty seriously. So it sounds like the only reason not to take the probation plea would be if dragginig out the case might cause the complaining witness to change her mind about prosecuting and cause her to stop cooperating with the prosecutor. That's a real longshot, as even when complainants want to drop domestic violence charges, the state makes it very tough for them to do it.
I understand why you would want to go back to india to be with your mother if she is undergoing surgery. The court would have to give you permission to leave the country, which they might do if you could document that the surgery was really going to happen and that it was life threatening and/or that the odds of her survival were not good. But because the court has no way of making you come back to the jurisdiction once they let you leave, they tend to deny requests. If you leave without permission (assuming your passport is not flagged and you ca get out, and you're not back by your court date, a warrant will issue for your arrest. That would subject you to an arrest when you tried to come back, and could cause you problems potentially even if you didn't, when you traveled anywhere outside of India. If the courts see you as a flight risk, then the prosecutor has already got your passport. You can't leave without it, and they can hold it until your case is resolved.
Sorry that I can't give you any better news. As indicated, the best you can do would be to try to document how ill your mother is and see if he can negotiate the trip to India for you.