It is possible to countinue studying jee advanced along with engineering syllabus in an engineering coll instead of taking long term

You can only get two attempts of jee advance that is in the year of completion of class 12th and in the next year. If you join a college in the same year as class 12th you have one year to get prepared for jee advance. Now engineering have it's own syllabus there are constant quizes, assignments, internals externals etc to prepare to for a exam like jee advance with all the extra work load is very difficult. I would suggest you instead you can take a year gap and then prepare for advance if you think you can crack the exam because IITs are worth your 1 year else simply take admission in any other college and focus on your engineering syllabus.
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