Dear Aspirant

I personally recommends you to do preparations of jee along with your 12 class because ncert syllabus is enough to crack your jee main along with question papers

And

,No , JEE MAIN is for B.E./B.Tech. and (B.Arch./B.Planning)Admission criteria to Undergraduate Engineering Programs at NITs, IIITs, Other Centrally Funded Technical Institutions, Institutions funded by participating State Governments, and other Institutions shall include the performance in the class 12/equivalent qualifying Examination and in the Joint Entrance Examination, JEE(Main). Admission to the Bachelors in Computer Application: is based on certain eligibility criteria’s. The eligibility criteria for most institutes across the country are similar. It is a must to fulfil these criteria’s in order to secure admission

I hope it will help you

Thank you