Filmmaker Shankar, who is all set to reunite with actor-filmmaker Kamal Haasan after two decades for the sequel to their highly successful 1996 Tamil film "Indian", says the idea to make the movie had been on his mind for a while.On Saturday, "Indian 2" was officially announced in the finale of reality show Bigg Boss Tamil, which Haasan hosts.Speaking on the occasion, "Enthiran" director Shankar said: "Every time I wrap up a project, I used to think of 'Indian 2'. For a long time, I wanted to make this film. Three years ago, a line struck me and I developed it into an idea for the project. I'm glad we are finally doing 'Indian 2'."Currently wrapping superstar Rajinikanth starrer "2.0", a sequel to "Enthiran", Shankar said he thought about "Indian 2" when he commenced work on this project.Haasan said he had never witnessed such a big launch for his film."This is a great platform to announce the film to over 6.5 crore who are watching the show," he said.In "Indian", Haasan played a dual role.AHe played the father and son.As a 70-year-old freedom fighter turned vigilante against corruption, Haasan won over audiences and critics alike."Indian", which had music by A.R Rahman, was released in Telugu as "Bharatheeyudu" and in Hindi as "Hindustani'.Also starring Manisha Koirala and Urmila Matondkar, the film bagged three National awards including best actor honour for Haasan.Rumours are rife that "Indian 2" could be Haasan's last film before he takes the political plunge.