You're only eligible for LMTSM MBA program if the candidate have a valid CAT/ NMAT/ XAT/ CMAT/ MAT/ GMAT/ GRE/ Thapar Entrance test score.
The applications will be available until February 2020. But the results for CAT will be announcced tentatively during the last week of January. This is just a tentative date and not a definite date. So waiting for CAT results might prove little risky. It is good if you apply for LMTSM before CAT results are declared. You have time until February to fill the application form. Please visit their official website to check their important dates for admission to their MBA programme. http://lmtsom.thapar.edu/index.php/admissions/mba/important-dates