Hello Amit, please check out the following link for detailed info on DUJAT cutoff: https://bschool.careers360.com/articles/du-jat-cutoff

Yes your overall rank might increase when best 4 is included, but it normally doesnt increase by a huge margin, plus you can only include subjects as suggested by DU norms for BBE/BMS courses, and not any best subject. 

You need a minimum percentile of 90 or above to get into a decent DU college for BBA-FIE course, and even with SC/ST/OBC reservation you need a percentile above 70-75.

So chances are negligible in DU, but you can try for private colleges.