I have been to Residency Towers -main street for buffet dinner lots of time as most of our office treats used to be arranged there. This place is awesome for large group (more than 10) gatherings. You can find mostly IT people having there treats here, also it is a great place for kid’s bday parties .For large gatherings you have book in advance.
Ambience is great , you will not feel it is crowded at any point in time as there is limited seating place and large groups usually are given a little separate place to sit.
In food, you will find lots of variety , north and south indian cuisine dishes are more , you will also find chinese (mainly noodles, fried rice and some gravy). Veg and Non-veg are kept separate so that there is no mix -up.
Usually they have one pasta dish which is always good(sure try that).Soups are served on table , you have only one choice in Veg and Non-veg.Desserts are the main attraction, lots of sweet varieties, ice cream and cakes.Make sure that you taste them all as all are good, for that you should not have too much main course .
Price is little less as compared to other hotels.Last when I went there it was around 400 -450 rupees(it could be more now).
All in all Residency towers is good for parties and also cheaper as compared to other hotels in chennai.I always prefer this hotel if I am giving the party :-)