There is a lot of confusion regarding the simultaneously enrollment for a regular degree and an distance education degree because there are two reports from UGC. I understand that you have started or currently doing your UG and you intend to go for one PG degree at the same time.
The reasons against this was, the issue with time spent on the course, attendance etc.
UGC had a committee that looked into the issue of persuing two degree simultaneously, one regular mode, one distance education mode.
The reasons for dual degree was the changing trends in education including PG education in India and overseas, accesibility of online courses and the competitive nature of the present day education and employment sector.
There is a UGC document from 2012,wherein a select committee states that one can take up a maximum of one additional degree program under open or distance mode from the same or a different university.(https://www.ugc.ac.in/pdfnews/0367166_morethanonedegree.pdf).
Recently, there was one more letter from UGC that was not in favour of a dual degree.(https://www.ugc.ac.in/pdfnews/5865506_UGC-Notice_For_Two_Degree.pdf)
What I would suggest is,
1.first enroll for the UG degree full time in a UGC recognized college and university.
2.Then seek the details of the course that you want to do distance mode, including the college and the university.
3.Then write to UGC in clear language about your current full time UG degree and the future distance course that you intend to take.
4.If UGC permits you, get it in writing and then contact the university wherein you are taking your full time course and inform the UG university officials that UGC has given you permission about the second distance degree and you would be enrolling for it. If they have no objections, then you win, go for both the courses.
5. If UGC refuses, then at least you have tried.
6.If the regular UG course university objects, then write back to UGC and seek guidance.
So, in short, there are two version of this, you wouldn't know for sure unless you try and contact UGC and get it in writing, this would be my view.