Surya on Shrewsbury St. in Worcester?
It will meet those needs -- it's reasonably priced and spacious enough. Not much in the way of atmosphere, but the food is very good, and if you tell them you want it spicy, they believe you and comply.
Bollywood Grill is a bit more upscale, and maybe less able to accomodate a large group.
So my friends and I went to Surya last weekend. We were a party of 10 and got seated immediately. The place was pretty empty, so I can tell that the booming chow biz on Shrewsbury St. is leaving them a bit behind. They're also tucked into a little strip plaza and harder to find.
The group ordered mostly the basics, like nan and Chicken Vindaloo and Tika Masala. All of it was just spicy enough to please. Everyone was satisfied with their meals and went home full. The service was a bit on the slow side, and orders were brought out as they were done, rather than all at once. At least this means the food was always hot from the oven. We'll definitely go back when we're in the mood for Indian cuisine again.