It's not just about Richard Parker but about being on a lifeboat for so many days!
Realistically a person would die off some disease or the other. Pyschological trauma alone would take you first.
I have no idea how to survive in such a situation.
You can't row your boat, the currents would take you wherever it decides to take you. Even if you have plenty of food, which alone is doubtful, you won't have water. There is a limit to how long you can go thirsty. All one can do is wait to be rescued.
Without food, water and a means to survive from the sun, you could at best survive 4 or 5 days considering you are in tip-top shape as long as you don't ingest sea water and have a mental breakdown. People have jumped into shark infested waters saying they will go buy cigarettes that's right around the corner.
Most of the longest survivors on the sea were already experienced seamen, either fishermen, merchant ship sailors or even those with sailing as a hobby, and were rescued by other boats. Regular people, little to no chance. Either be rescued in a few days or the sea will have you.
Those who really survived long durations adrift did not lose their distillation equipment, food and shade like that idiot Pi did.