What are srinivasa ramaanujan's discoveries?
Here are few links for the answer to your query:
https://www.meritnation.com/ask-answer/question/article-on-contribution-of-indian-matematicians-in-the-field/articles/7567851
https://www.meritnation.com/ask-answer/question/who-is-ramanujam/determinants/7267663
You can also search the same over Internet to gather information about his contributions to Mathematics.