Hi aspirant,

See there are two scenarios in this case. as you have completed your intermediate in year 2018 you would not be eligible to write the JEE main examination as the the eligibility rule says that candidates are eligible only for three consecutive years starting from the year she appears for the board examination and you have over pass it. Now since you are diploma holder you can write the JEE main examination and even qualify for JEE advance but it is important to note that NITs & CFTIs do not consider the score and rank of a diploma holder in JEE Main for admissions to their colleges. However you can use the the result to get admission into various other government Engineering colleges which accept JEE mains scores.

Hope it helps!!