To be eligible for Startup India Registration, a startup must fulfill the following criteria:

The startup should be incorporated as a private limited company, a registered partnership firm, or a limited liability partnership (LLP).
The entity should be less than ten years old from the date of its incorporation.
The annual turnover of the startup should not exceed INR 100 crores in any of the financial years since its incorporation.
The startup should be working towards innovation, development, or improvement of products, processes, or services, or if it is a scalable business model with a high potential for employment generation or wealth creation.
The startup should not be formed by splitting up or reconstructing an existing business.
https://www.registerkaro.in/startup-india-registration