Dear karthikeyan. M,
Tirupati Balaji Idol is a mystery. Learned people have written
that it could be Muruga, (because Muruga temples are always
on a hill), Uma (because large lock of hair is found at the back
of the image), Siva (because even today the priests do pooja
with bhilva and not tulsi). But no one has said that it is Buddha.
Brahman is nameless and formless, we give name and form and
call it as different gods. Arunachala Ashtakam, Bhagavan Ramana.