“Wish I grow to be as strong and young as you,” he added.
Alongside the special birthday message, Hrithik posted a photograph of him sharing smiles with his father.
Rakesh’s wife Pinkie has also penned a heartfelt note for the former on Instagram.
“Happy birthday to my partner for life and many more..keep guiding us always ...have walked the path with you and learnt so much...will hug you..holding your hand forever thru our journey with the blessings and love of our elders who have departed and wishing you from wherever they are,” she wrote.
Rakesh is best known for helming films such as ‘Khoon Bhari Maang’, ‘Karan Arjun’, ‘Koyla’, ‘Kaho Naa... Pyaar Hai’, ‘Koi... Mil Gaya’ and ‘Krrish’ franchise.