hi,
see you may go for diploma in automobile engineering or b.tech in automobile engineering once you completed your 12th course. there is diploma engineering admission entrance test held as per state wise, in some of the cases admission is based on 10th/ 12th merit wise.
to admission in b.tech course of 4 years duration you may apply for state wise entrance test like wbjee, keam, tancet counselling . all India level entrance exams like jee main.
so now it depends on you. you have to take preparation from atleast 6 months before entrance exams.
if you have any more query you may ask in comment section.
careers360 has online coaching for jee main, it includes online lecture series, mock test, doubt solving sessions, previous years solved papers. overall this is a complete package to boost your performance,
https://learn.careers360.com/jee-main-coaching/?utm_source=%20QnA
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