SMEAT

SASTRA has two admission streams known as Stream-1 and Stream2-. The details about the both streams are given below:
Stream-1 : Based on JEE Main score+12th Marks and applicable for admission of 70% of seats. The 25% and 75% of weightage are given to JEE Main percentile and 12th marks respectively. So in your case your combine score will be as follows :-
82.5x0.25+12th Marksx0.75 (Your 12th Marks are yet to be declare)
Stream-2 : This stream is applicable for admission in rest of 30% seats. This stream is purely based on 12th marks (Normalized aggregate). This stream needs above 96% of marks for admissions hence not explaining here. However if you are scoring above 95% in 12th than apply for both of above streams
So from above in the absence of your 12th marks it is difficult to make the prediction about the admission. However if you are scoring above 80% in your 12th can be hopeful here for admission.

The admission process of IIM Trichy takes into consideration the candidate's performance in CAT, performance in Personal Interview (PI) and Written Analysis Test (WAT), academic record and relevant work experience.
The criteria that would be used to select candidates for Personal Interview and Written Analysis Test (PI & WAT) are shown below:
1. Quantitative Aptitude (Section 1) : 80 percentile
2. Data Interpretation & Logical Reasoning (Section 2) : 80 percentile
3. Verbal & Reading Comprehension (Section 3) : 80 percentile
4. Total (Overall Percentile) : 94 percentile
So from above you needs the minimum 95 percentile in CAT exam but for admission your CAT percentile should be above 98.