My understanding is, you can easily apply for a 5- or 10-year tourist visa to India. The only problem is, you can only stay six months at a time, then you have to leave India for at least two months before re-entering India for up to another six months. It is the longer-term Entry Visas which are limited to those of Indian descent.
After you are married, as a spouse of an Indian national, you can apply for a PIO (Person of Indian Origin) card, which is valid for 15 years and you can stay in India as long as you like and leave and return whenever you want - so, be sure to get that once you are married!
