The two best Indian restaurants that I know about are:
1) Shalimar (Pakistani-Indian food)
This is often very crowded. It can be a bit chaotic when ordering but many people feel that this restaurant is well worth it.
2) Bomboy Garden
A nice buffet with selections of both vegetarian and nonvegetarian entrees. It's in Newark but close enough to Fremont that it's still well worth visiting if you want to eat at a good buffet.