Hey !
According to your query you are talking about eligibility criteria, The courses in Petroleum engineering are offered both at undergraduate and postgraduate level. Btech program in Petroleum Engineering requires a minimum 10+2 qualification in Science stream with Physics, Chemistry and Maths with around 60 percentage of marks in aggregate. As you are a pcb student you cannot take up Engineering (any course in engineering) in your undergraduate level.
Check the below link for other information regarding petroleum engineering like scope and the subjects present.
https://www.careers360.com/petroleum-engineering-course
Hope this helps
All the best !