Shikhar, the CAT percentile is only valid for one year, i.e. if you want to take admission in the next year, you will have to retake the exam.

Although IIM Ahmedabad has a provision for deferred admission. This means that if you have work experience of less than 2 years, you can defer or postpone your admission to minimum 1 and maximum 2 years, get the required work experience of at least 2 years and return to get your seat in IIM-A.

Also some colleges like Great Lakes, Chennai may accept your previous year's CAT score for admission too. Other than that, your CAT score and percentile is valid only for one year and you cannot take admission on its basis in the next year.