Actor-singer Gippy Grewal, who will be seen portraying the role of Subedar Joginder Singh for a biopic titled on the martyr's name, says it is a big responsibility to play a national hero on screen.Asked how big it is a responsibility to portray a national hero, Gippy told IANS over phone from Mumbai: "It's a big responsibility. I feel it is a challenge to do anything, but if a personality like this needs to be portrayed, then it becomes really big." Gippy, whose real name is Rupinder Singh Grewal, says one has to do a lot of homework to portray a real life person on screen."One has to go into a lot of details because our motive of making such biopics is to bring these people alive on the silver screen in front of the audience... People don't know much about Subedar Joginder Singh... He is a Param Vir Chakra winner and did so much. But there are so many other things that need to be shared... So, we want to show that in the film."It's a big responsibility as we have to ensure no one gets hurt and we make it properly. So we have to keep everything in mind."Gippy, who has sung hits like "Angrezi beat", "Chandi de challe "and "Khulke dulke", says he will also be singing a track in the upcoming biopic, which will release on April 6 next year.