No, once the invention is in the public domain, it cannot be patented anymore. Inventors should not disclose their inventions before filing the patent application online or offline. However, under certain circumstances, the Patents Act provides a period of 12 months for filing of patent application from the date of its publication in a journal or its public display in an exhibition organized by the Government or disclosure before any learned society or published by the applicant for the same author and same inventor only.