Hello Aspirant,

See admission to B.Tech. courses in IIT Delhi is done on the basis of JEE-Advance score and to appear in JEE-Advance you must qualify JEE-Main. With 68% marks in class 12th you are eligible for JEE-Advance provided that you qualified JEE-Main as well for that year and on the basis of that JEE-Advance score you can get admission in IIT Delhi if you meets the cut-off rank for it.

For IIT Delhi there is no any specific criteria of percentage required in class 12th, but you only need to be pass in class 12th.

Maximum attempts allowed for JEE-Advance is 2 in 2 consecutive years, first attempt in the passing year of class 12th or equivalent examination and second attempt in very next year to that. Similarly for JEE-Main maximum attempts allowed for JEE-Main is 3 in 3 consecutive years, first attempt in the passing year of class 12th or equivalent examination and second attempt in very next year to that followed by third attempt in third year.

For more details kindly check out the links given below :-

JEE Advanced Eligibility Criteria 2022 - Check Age Limit, Domicile, Average Marks (careers360.com)

JEE Main Eligibility Criteria 2022 (Released) - Check Age Limit, Qualifying Marks, Number of Attempts (careers360.com)

I hope this information helps you.

Good Luck!!