When it comes to preparing for the CAT (Common Admission Test), there are several free and paid sites and online tools that can be helpful. Here are some of the best options:

1. Official CAT Website: The official CAT website (iimcat.ac.in) provides valuable information about the exam pattern, syllabus, and official mock tests. It’s a great starting point for understanding the test structure.

1. T.I.M.E: Triumphant Institute of Management Education (T.I.M.E) is a popular coaching institute in India. They offer both free and paid resources, including study materials, online mock tests, and video lectures. Their free resources can be beneficial for self-study.

1. Career Launcher: Career Launcher is another reputed coaching institute that provides comprehensive study material, online classes, and mock tests. They have both free and paid resources, including a mobile app for CAT preparation.

1. Handa Ka Funda: Handa Ka Funda is an online platform that offers a variety of CAT preparation materials, including video lessons, live classes, study material, and mock tests. They have both free and paid resources, with the option to choose specific sections or the complete package.

1. Oliveboard: Oliveboard is an online learning platform that offers free and paid CAT preparation materials, including video lectures, topic-wise practice questions, mock tests, and performance analysis. They also provide a mobile app for convenient studying.

1. Cracku: Cracku offers a range of free and paid resources for CAT preparation, including study material, section-wise practice questions, mock tests, and previous year question papers. They also provide detailed performance analysis and solutions.

1. GMAT Club: Although primarily focused on GMAT preparation, GMAT Club has an active CAT forum with a wealth of information, study materials, and practice questions. The forum is a great place to interact with fellow aspirants and experts.

1. Pagalguy: Pagalguy is a popular online community for MBA aspirants. Their CAT forum provides discussion threads, study materials, preparation tips, and insights from previous test-takers. It’s a great platform to connect with like-minded individuals and seek guidance.

Remember, it’s important to create a study plan and be consistent with your preparation. Utilize a combination of resources from different platforms to get a comprehensive understanding of the CAT exam and practice effectively.