Can the subject cut be lower this year? I am getting 10 in maths and a total of 137. Am I expected to clear JEE advance 2019.

Hello Bhishma,
As per previous year cutoffs, the subject wise  cutoffs usually lie between 9-12 marks for different categories. As you are getting 10 in maths, you might just clear the sectional cutoff. Your total score of 137 is good enough to clear JEE advanced and fetch you a all India rank of around 20,000.
So, keep your hopes high, if you clear maths sectional cutoff, you surely will get a rank around 20k in JEE Advance.

Follow this link for better predictions-
https://engineering.careers360.com/jee-advanced-rank-predictor

Good luck!