Delhi taxi drivers raping or otherwise sexually assaulting female passengers has happened repeatedly over many years. Many of them don't get reported to the police, but some of them do get reported to medical staff.

I see no evidence that Uber is less safe than the alternatives there, and I say that as someone with lots of experience in Delhi.

Radio taxi companies and Uber had been seen as an improvement in safety/security for solo women travelers in Delhi -- an improvement over what used to be before -- but some of that may have been based on wishful thinking. The difference now is that at least the radio and uber drivers are now in a better position for being caught and punished than used to be the case. Thank technology and increased competition for that.