If I start jee preparation from now, can I crack jee?

Yes there might be a chance if you devote your full time to study from now.Don't waste your time on social media.Start from basic books first like ncert as the questions of jeee mains are mainly based on ncert.Practice and solve each and every question of ncert.Join online test series programmes of good coaching institutes or purchase practice papers of jee mains and start solving questions.Also try to solve previous years questions to get an idea of what is the level of questions asked in jee mains.Also some questions are repeated from previous years papers.
You can do it.Just be confident and motivated!
All the best!:)