There are several buses of APTDC running between of Tirupati and Chennai.

Here I am providing list of buses between Chennai and Tirupati.
CHENNAI – TIRUMALA TOUR:
CHENNAI- TIRUMALA TOUR Daily by A/C Coach with Seegra Darshan – ONLINE BOOKING 1 Day tour covers Tirumala, Tiruchanur Dep. 7.30 PM Chennai/- Arr.7.00 PM Chennai next day
FARE: Adult Rs.1300/- Child Rs.1040/-(Includes Accommodation.)

CHENNAI – TIRUMALA TOUR:
CHENNAI- TIRUMALA TOUR Daily by Volvo A/C Coach with Seegra Darshan – ONLINE BOOKING 1 Day tour covers Tirumala, Tiruchanur Dep. 5.00 AM Chennai Arr 10 PM
FARE: Adult Rs.1350/- Child Rs.1080/-(Fare includes only Breakfast)

CHENNAI – TIRUMALA TOUR:
CHENNAI- TIRUMALA TOUR Daily by A/C Coach with Seegra Darshan 1 Day tour covers Tirumala, Tiruchanur Dep. 5.00AM Chennai Arr 10 PM
FARE: Adult Rs.1250/- Child Rs.1000/-(Fare includes only Breakfast)

CHENNAI – SRISAILAM TOUR:
CHENNAI –SRISAILAM TOUR (Every Friday)A/C Coach Srisailam, Mahanandi,& Ahobilam Dep 10PM (Friday) Arr.5 AM (Monday)
FARE: Adult Rs.2500/- Child Rs.2000/-Including Transportation, Accommodation, Rope way & Boating