Tirupati is the site of the famous Tirumala Balaji Temple. So Tirupati is a tourist attraction, and a developed area. I can completely understand your concerns regarding the food, weather and language in and around IIT Tirupati.
I can enlighten you about the mess food of IIT Tirupati. It is an amalgamation of North and South Indian dishes. The menu generally consists of Dal, Sambar, Cury, Curd, Salad and Rice. Mess food can’t be compared to homemade food, but it is decent enough and comparable to the mess food at other IITs.
The weather of Tirupati is extremely hot from April to May, with temperatures around 41-43 degrees. But these are the months of college vacation, so you need not worry. The monsoons take place between July- September end, and the winters are quite warm and comfortable. The place is quite liveable.
The common language of Tirupati is Telugu, but as it is a famous tourist attraction, the local vendors and autowalas know good-enough Hindi. Inside the campus, English is the commonly spoken language by professors and students. Language usually won’t be a problem in and around the campus.
You’ll have a good time at IIT Tirupati, irrespective of your cultural background.