This review is solely for the lunch buffet:
Tamba offers perhaps the best Indian lunch buffet in town. Unlike most Indian restaurants in Vegas, the cooks at Tamba don't focus on a bland tourist palate. And as a result, they don't produce spice-less offerings.
What the buffet does offer is an amazing array of vegetarian options--tasty, spicy and delicious options--chana masala (chick pea masala), palak paneer and various other vegetable-based deliciousness. But the buffet isn't solely for the vegetable lover. The Tamba buffet also carries several chicken dishes in well-crafted sauces. If you've eaten at a few Vegas Indian buffets, you'll know that tasty and spicy foods are rare. So if you're near the south side of the strip for lunch, you can't do much better.
As for the dinner or regular dishes (not in buffet form), I haven't tried them, but several India-born friends have told me that Tamba is the best Indian restaurant in town.