This is a Tamil language biopic of one of the greatest spiritual gurus and philosophers of Bharat, viz. Ramanujacharya Swami.
He was still well known as the key proponent of the Vishishtadvaita form of Vedanta which has followers all around the country.
Born with a spiritual bent of mind, a keen and inquiring intellect, he was first tutored in Advaita. Unconvinced about the theory fully in regarding oneself as the supreme Brahman, while also agreeing with its premise that God isn't someone distinct from oneself, Swamiji came up with the philosophy of Vishishtadvaita. This path proclaims that while we are Jiva - that is individual souls - we are also a part of Paramatma - the supreme soul.
This comes both as a solace and a great motivation for humans to strive to realise this.
Ramanujacharya was a great devotee of Narayana and is known to have performed many miracles in life. He survived and thrived despite strong opposition to his way from Shaivites who were in power those days.
The secret mantra he taught was - Om Namo Narayanaya - and is credited to spreading it among the masses despite the opposition of orthodoxy who considered religious supremacy to be the vanguard of a select few.
After a life well lived, he gave up the body at will as Jeevasamadhi.
These aspects of Swamiji's life are well known, and equally well represented in this film.
If you want to understand Swamiji's life and Bharat's cultural history better, do watch this film.