Siri, truth be told, any Educational Institution conducts mock tests tougher than the original examinations. This is a strategy to prepare the student for the worse. Now if you are able attempt 25 and you get 15, you are getting 60% of your answers right. That is not a bad thing. In JEE Mains, you will go as far as even 80 and above looking at Narayana's strategy. This is not the time for you to panic and be disappointed in your performance. So continue to attempt mock tests not just given by the College but also available in other sources. Divide the syllabus into Class 11 and Class 12 and the topics as "Need to Learn", "Weak" and "Strong". Now it is important to check the weightage of each topic. In Physics, Modern Physics take the top slot with 5 questions. Heat and Thermodynamics, Optics, Current Electricity, Elcetrostatics get 3 questions each. Magnetic has 2 questions and the rest get 1 question each. In Chemistry, Transition Elements and Coordination Chemistry, Periodic Table and Representative elements take 3 questions slot. Thermodynamics and Gaseous state, Atomic structure, Chemical Bonding, Chemical and Iconic Equilibrium, Solid State and Surface Chemistry and Nuclear Chemistry and Environment get 2 questions slot eacch and the remaining get 1 question each.In Mathematics, Co-ordinate Geometry gets 5 questions. Limits, Continuity and Differentiability, Integral Calculus get 3 questions slot each. The rest get 2 and 1 questions slot. For complete breakdown, please read our article: https://engineering.careers360.com/articles/jee-main-syllabus-weightage . Once you complete a topic, try to practise the concepts and write down the important points and paste them somewhere that you can see. Practise questions from that topic.