How to prepare for IIT ? 4- Which coaching/ Institute should one join for IIT?

This is the most difficult question. Answer of this question is to be decided by the candidate itself. I will guide and tell what factors one should take into consideration. See the following table it is just a sample format that I have prepared one one add more points and remove or modify the point.

             This is a 300 point table. You can use it to decide which coaching one should use. One can change the point allotted according to them. Then start giving the point to coaching A and Coaching B. How to allot the points in the factors. Suppose we have to allot in the faculty qualification row if all faculties are IITians give 30 out of 30 points. If two are IITians one is NITians can give 25 points. Like that you can award the points. Years of experience: 4 points per year of experience up to 5 years above 5 years give full points. Friendliness how to check it? Go and meet the faculties interact with them if possible. Ask previous year students if possible. 

4th point is Fees Structure if someone has not economic problem then he can leave that point but many have this problem. Coaching fees may not come into the budget so give more point is fees is lesser. 

In infrastructure you have to see the classroom size how many students can sit in a class if it is less than 60 give full points. If it is between 60 to 100 give 3/4^th point and like that you can decide.
Let us understand why If classroom size is small then number of students will be less then teachers can focus on each student. Suppose there are 300 hundred student seating in a class one cannot be able to focus on individual student. There will not be any difference between a video lecture and classroom study. When it comes to doubt clearance either other teacher will handle it or student will not be able to ask doubts after the class because it will take a whole lot of time for one doubt to reach near the teacher.

Similarly other factors can be understood if anybody has any specific question regarding the factors can comment in the comment section. I will try to respond as per my schedule. 

You can add other factors too if you have anything in your mind and allot that factor and give it some points.

This way you can compare the coachings. Choose the most appropriate.