Hello Aspirant,
The basic difference between two is following.
NRI quota :
Candidates should fulfill the following minimum eligibility criteria to seek admission under Foreign and Non Resident Indians (NRI) Candidates Category. A pass in the 10 + 2 or equivalent examination of the respective country.
Management quota :

On the other hand Management Quota means theseseatsare reserved for those people who actually didnt qualify the eligibility criteria for getting a seat in college but are willing to spend almost two to four times the actual fee of the college. It is like the direct admission process in colleges.

Hope you understand now
All the best!

Hello,

The quota is for students other than appearing for the entrance exam of various colleges for various courses, nonresident Indian quota seats are meant for students who reside outside India and students who have sponsorship from NRI guardians.

Management quota is the other quota which exists which means seats reserved for candidates of management of trust, owners or authorities of the institute who are running the university or college.

There are different criteria laid down by each university or institute by rules provided to them with UGC or AICTE or deemed university which provides recognition and affiliation of the institute .

Hope this helps, All the best!