hi,

see it depends on your interest for any particular course. if you have interest for current electricity and electrical instruments you may take electrical maintenance as bifocal or vocational subject. however it would increase your knowledge of physics which is related with electrical engineering, electromagnetism etc. which help you in near future if you chose engineering in relevant stream. however this subjects has no special significant roles in jee main or any other entrance or board exam. for entrance exam for engineering you have to study physics chemistry and mathematics and for good score you have to master the three subjects. so now it depends on you whether you are capable of taking extra subjects or not beside preparation of board exam and jee mains exam.

hope you may understand.