PANGA is the story of a mother trying to fulfil her dreams. Jaya Nigam (Kangana Ranaut) is a pro at Kabaddi. She slowly rises and also becomes the captain of the Indian Kabaddi team. She is meanwhile married to Prashant (Jassie Gill) and gets pregnant just before she is to go for a major tournament. She still assures her seniors that she'll be back soon.
However, her son is born prematurely and with a very weak immune system. The doctor informs that they'll have to take care of the baby tremendously and only then will he have a normal growth. Jaya hence gives up her dream. She takes up a job in the railways and divides her time between her work and raising her son Adi (Yagya Bhasin).
7 years pass. Jaya is finding it difficult to fulfil the responsibilities expected from her. Moreover, she meets Meenu (Richa Chadha), who was in Jaya's team and still plays Kabaddi. One day, Adi suggests that his mother should make a comeback in Kabaddi. He persuades Prashant and both begin nag Jaya. Jaya is unsure as she feels she has grown old and is not that fit. Prashant suggests that Jaya should pretend to make comeback and a month later, she can claim that she didn't get selected. Jaya hence begins her practice.
At first, it's difficult for her but soon, she gets enthusiastic about the whole process. After a long time, she realises she is finally living her life. Two months pass and one day, she tells Prashant that she wants to continue practicing and try to get into the Indian team. What happens next forms the rest of the film.