There is no cut off for a January Exam . After April Exams result is announced, then you will get to know about the cut off to be eligible for JEE Advanced.  If you apperared for both the exams, then your best result will be considered . If you apperared for only one exam , then only that score would be considered . So try to practice more and give April Exam which is now shifted to last week of May . It would improve your score .

Hello,

Cutoff and Rank List of JEE Main 2020 will be released along with the result of JEE Main April Session. Cutoff is not released for January Session. Cutoff is released after conduction of both sessions that is one in january and one in april.

The JEE Mains April Session is postponed due to COVID-19 Epidemic and is scheduled to be conducted in last week of May. The Cutoff and rank list will be released along with the results of JEE Main second session, that is scheduled to be conducted in May

Click at this link to know more - https://engineering.careers360.com/exams/jee-main

Hope this was helpful.