Rajesh died on Thursday following a heart attack while he was shooting for a southern film in Hyderabad. He was 66.
His role of astrologer Guran in "Lagaan" is known as one of his most notable on-screen outings.
Aamir, 50, took to Twitter to pay him a tribute.
"Yesterday we lost someone from the Lagaan family...Rajesh Vivek. You will always remain in our hearts Baba. Love. A," tweeted the "Dhoom 3" star.
The last rites of the actor were conducted yesterday here in presence of his family, friends and several film personalities like filmmaker Ashutosh Gowarikar, actors including Akhilendra Mishra, Daya Shankar Pandey, Amin Hajee and Raj Zutshi.