In my view you still have age on your side and you CAN pursue a course from IIM. However, are you sure that you have sufficient interest to pursue this course? You will face quite a difficulty in getting selected in one of those B schools or IIMs since a lot of students from different backgrounds fight for the seats in such college.
I am sure you would have to leave your current job, to even think about studying for appearing in CAT. I don't think your break will affect you in anyway though.
A weird advice...when you have enjoyed success for a long time it might be time for some sort of decline...so take care when you go ahead with any advice...There is always a cost of failure from risk taking...but careful risk taking through definite planning can shorten such cost in case of failure in an endeavour.
I personally would have wanted to remain in the field and search for more interesting opportunities in this field itself however no two people are same....Will you have financial support from family in case you do choose to pursue MBA?
Prepare a questionnare yourself and see for yourself. Also know everything about CAT exam beforehand and calculate your success chance as well. For all I know CAT exam is mostly about fast math and logical reasoning skills.
MBA of any sort will definitely add value to your current degrees. Also the additional skills that you will gain while pursuing MBA from a B SCHOOL will enhance quality of your knowledge and life both...
I am 24 now so I am not thinking about it but if I had become CA at 22 I would have definitely given Civil services a go.