Gender related crimes against women already very common in India. I believe they will intensify in the future.
Either way with <850F:1000M gender ratio, for India's population scale there will states full of unmarried men. I believe though crime will be a common place, it won't be possible for all men to indulge in crimes(Which will be a civil war situation at the scale we are talking about).
Either way a lot of men will have to marry men.
IMO it will result in a lot of angry and depressed single men who resent society. If you put someone into a corner without many options they can become desperate and violent. This imbalance in India and China will become very dangerous in the coming years
Attraction is generally not a choice (there's probably some things you can do deliberately over time to shift it a little bit, but...). Marriage, OTOH, is a choice, and its a choice that historically is motivated by many things, with attraction quite often not being a main factor.
The real problem with "have to marry men" isn't that attraction isn't a choice (as marriage and attraction are not the same thing) but that marriage is not mandatory.
Both China and India have large gender imbalances -- and with a border conflict... :-(
"May you live in an interesting time" was a Chinese curse, I think?