First of all I would like to clear you that anybody cannot pursue Undergraduate course and Postgraduate course simultaneously because it is not valid and for Postgraduate course one needs to qualify the minimum eligibility requirements in his/her Undergraduate program but on the other hand there are some integrated programs like B.Tech+M.Tech which is 5-Year program offered by some of the institutions such as NIT/IITs/GFTIs/CFTIs. And also in DU there is no course like B.Tech+MBA and through JEE-Mains admissions are provided only in BE/B.Tech/B.Arch./B.Plan. courses and if you want to pursue MBA after your B.Tech then you can applu for any of the Management entrance exam like CAT/XAT/MAT/GPAT and so on. You can complete list of management entrance exams from the link given below :-
For complete list of courses offered in DU kindly check out the link given below :-
I hope this information helps you.