Hello astha 

If i m not wrong the exam for blat is of 150 questions of 450 marks you attempted 137 ques out of which 120 claim to be correct and -1 negative marks that means one third deducted so you have calculated your marks its better you should predict your rank using previous cutoff yourself using our link 

 https://www.google.co.in/amp/s/law.careers360.com/articles/blat%3famp