Dating and marriage culture
This is because India has about 29 states, each with a different language, customs etc.
Dating as we Westerners think of it, involves trial and error.
In this sense you can target your search in a way that would never be possible off of the Internet.
This holds true for dating outside of the Indian culture.
For other parents the reasons for not wanting their child to marry or even date outside of their religion, race or nationality varies, but the result is still the same.
In Western culture we are used to direct - in your face confrontation between a woman and man. Instead, the way to address differences is in private so as to not to embarrass the other person.
A big factor as to whether he will date is his parent's opinions, beliefs, and tolerance.
If you are interested in dating an Indian man, I would suggest that you try to learn about his family and culture as this will give you an idea of his beliefs about marriage and family.
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What beliefs do his parent's hold for him regarding marriage and family?