Mr Subramanyan passed away in Vadodara on June 29.
Mr Solanki met the artist’s daughter Uma Padmanabhan and handed her the letter.
In the letter, Ms Gandhi described Mr Subramanyan as a “brilliant and versatile artist”.
“He was a many-splendoured personality: freedom fighter, scholar and creative genius, inspirational teacher to generations of young artists, and a man of boundless warmth, generosity and joie de vivre,” she said.
Meanwhile, at a condolence meeting held today, Shubhanginidevi Raje, chancellor of the Maharaja Sayajirao University, paid tributes to Mr Subramanyan.
One of the pioneers of Indian modern art, his death left a big void, she said.
About one thousand people from across the country attended the condolence meeting held on the Fine Arts faculty premises in Vadodara.
In a career spanning over six decades, the multifaceted artist, who lived in Vadodara, had been a painter, sculptor, muralist and print-maker besides writer of children’s books.
He was awarded Padma Vibhushan in 2012.