Yes all PCB Group students can fill Agriculture stream under BCECe.

However students must have Physics and Mathematics as compulsory subjects and opt for elective among Biology /Biotechnology /Vocational subject in 12th from recognised University to be eligible.

https://engineering.careers360.com/articles/bcece-eligibility-criteria

Only Resident of Bihar as candidates can be eligible for reservation to Bihar Engineering colleges via BCECe. 

So outside state of Bihar are simply not eligible for reservation of seats in BCECe. 

Detailed eligibility criteria below  

https://engineering.careers360.com/articles/bcece-eligibility-criteria

As per the eligibility you need to have passed your 10+2 or equivalent exam with Physics and Mathematics as compulsory subjects and Chemistry/ Biotechnology/ Biology/ Technical Vocational subjects as optional subject. There is nothing about the compartment student officially. You can also check the eligibility with the given below link.

PCB Group students can go for the courses B.V.Sc. & A.H., Physiothearpy, Ocupational Thereapy, B.Sc Lab tech, B.Sc OT Assistant, B.Sc Exray etc. through BCECE. You can also refer the below given link for the further information.

http://bceceboard.bihar.gov.in/pdf_Adv/ADV_BC18_46.pdf

Good Luck!

Not necessarily its asked from previous year papers. However there is no particular weigjtage but good chances of questions being asked from previous year papers. 

Generally fresh questions are asked year on year which will comprise of 80% of paper.

You can check all previous year papers below and compare

Hey Jyothi singh,

Yes you are elgible.

You can even give a quick glance to the elgibilty criteria mentioned below.

BCECE 2019 Eligibility Criteria

Nationality:

Candidates must be citizens of India to be eligibel for BCECE.

Qualifying Examination (QE):

Candidates who have passed or will be appearing in their 10+2

Hello Sonu,
Kindly clarify your query so we can help in solving your doubt.
If you are asking about admission to engineering stream then BCECE Counselling for admission to engineering stream courses was conducted in three rounds.
Good Luck!