Rensil, who has written scripts for 'Rang De Basanti', 'Kurbaan', 'Student of the Year' and more recently 'Ungli', said Ratnam is highly impressed by the way the script is shaping up.
"Mani and I have been writing something since 2007. Mani wants me to direct it myself. It's a biopic but not on any sports personality or freedom fighter. It's about a person who travels from rags to riches. A man who built and set up his own company," Rensil said.
Ratnam's last Bollywood outing was Abhishek Bachchan-Aishwarya Rai starrer 'Raavan' in 2010.