On the question of 'is it better to exclude non-rapists than include rapists', especially in the case of claiming that their service is safer than taxis (which they do all the time, unless someone points to a counterexample at which point they disclaim all responsibility): I would say yes.
Is it legal to discriminate against employees who've been accused but not convicted of a crime? Well, no.
Is anything else Uber is doing in India legal? No.
So… if they're breaking the law anyway, plus making sure to hide everything they do, including basic contact information, from anyone who might need to contact the company (to the extent that the government themselves had to hire a driver just to get in touch with someone), I feel like denying employment to someone convicted of a violent sexual assault would probably be the least unethical thing going on with Uber in India.
I think it's better to quantify it and change the question to 'Is it better to include X non-rapists and Y rapists than to exclude X non-rapists and Y rapists.'
'Is it better to include into the set of Uber drivers, 10 non-rapists and 1 rapists or to exclude 10 non-rapists and 1 rapists.'
Probably the latter.
'Is it better to include, into the set of NYC residents, 5 million non-rapists and 3 rapists than to exclude 5 million non-rapists and 3 rapists.'
Is it legal to discriminate against employees who've been accused but not convicted of a crime? Well, no.
Is anything else Uber is doing in India legal? No.
So… if they're breaking the law anyway, plus making sure to hide everything they do, including basic contact information, from anyone who might need to contact the company (to the extent that the government themselves had to hire a driver just to get in touch with someone), I feel like denying employment to someone convicted of a violent sexual assault would probably be the least unethical thing going on with Uber in India.