As per 2019 qualifying cutoff General category,  You should have 40% of 200 marks. You will have to score 40 marks in each- MAT and SAT and overall 80 to qualify. But the selection for the second round depends on Telangana cutoff.

You can check the previous year cutoff with the given below link.

https://school.careers360.com/articles/ntse-telangana-cutoff

Cutoff in General category in 2017 was 118marks and in 2016 it was 126marks, hence going by trends average ofboth scores comes around 122marks.

Which means plus or minus 15 is fair expected rnage of cutoff nd hence you can expect 107 to 137 marks as rangr for Telangana NTSE Stage1 in General category

https://school.careers360.com/articles/ntse-telangana-cutoff