If your board follows the "Best of 5" rule, your lowest-scoring subject, which in this case is SST, may be excluded from the percentage calculation, provided SST is not a compulsory subject in the best five. Generally, core subjects like Maths, Science, English, and Hindi are considered, while optional subjects like AI may also be included. However, the final decision depends on your school's or board's specific guidelines. It's best to confirm with your school authorities for accurate information regarding the evaluation process.