It is very much possible to prepare for CAT in 4 months .In fact some topper had prepared for few weeks to bell the CAT.But it depends if you are first timer or retaker.

To start with i would suggest you to take an diagonstic test or solve 1 past year Cat paper to know your strength and weakness.Assuming you are self preparing

Make a note of strong,moderate and weak areas.Work more on weaker areas also side by side practice moderate and strong areas too .

Few topics like Permutation and combination ,Probability which have little to no weightage can be left .So can be the vocabulary part in VA.

But practice more topics like RC,Parajumbles,Geometry ,Arithematic and Speed,Distance and Time,DI and LR (particulary game based caselets).

Join mock test series after 1 month of preparation .if you are first timer then Career launcher (CL) .Also Handa ka funda is a good option .If you want coaching again Handa ka Funda is a very viable option.

Also note it is important to analyse the mock rather than just solving and moving.Start with 1 mock per week then move to 2-3 mocks per week.

A week before try to solve past Cat paper with 70-80% accuracy .A day before just relax.

All the Best.

Hello Mayank .. Yes it is possible to to crack the exam in five months by joining good classes , You must do proper preparation by proper noting of points and then doing good revision, and then appearing for mock test to know the status of studies so that u can work upon it more hard. you have to be calm and concentrate more as u will be having less time and must avoid the last moment studies which may create more choas.

all the best!