Vijay had called on Mukherjee and handed over a representation to this effect recently.
"I would extend my hearty thanks for your representation to the President to expedite steps to declare Tamil as language of the Madras High Court", Vaiko said in a letter sent to Vijay.
"Your speech in the Upper House on July 31, 2014 making a demand to observe Thiruvalluvar's Birthday as glorious Indian languages day in all parts of the country has won the hearts and minds of Tamils", Vaiko said.
"I extend my sincere thanks on behalf of Tamils and also on behalf of MDMK party", he said.