Hello Komal,

It is clearly mentioned on the GATE website:

"GATE-2019 score can be uploaded on the website upto April 01, 2019 although you should have previously submitted your Online Application on / before January 31, 2019. However, you can improve your chances of being screened in to the Selection Interview by additionally applying on the basis of Online Exam. The last date for applying on the basis of Online Exam is January 31, 2019. Please note that the cut-off GATE scores for screening into Selection Interview will be known only after the last date for applying for Online Exam."

Hope this helps.