Sudhanshu, the cutoff of PRMO varies every year depending on the level of question paper, performance of the appearing candidates and previous years' cutoff trends. Upto 300 students from class 8 to 11 and about 60 students from class 12 are selected for the next round from each state/ region.

PRMO 2020 is yet to be conducted in August 2020. Although I can provide you with the cutoff for 2019 and 2018. Now Bihar is divided into two different regions for declaring the results- North Bihar and South Bihar. Technically the places above river Ganga come under North Bihar and those below Ganga come under South Bihar.

For North Bihar, the cutoff for students from classes 8 to 11 was 14 marks in 2019 and 12 marks in 2018. For South Bihar, the cutoff was 7 marks in 2019 and 2 marks in 2018. Hope it helps.