Yes, you can pursue Post-Graduate programmes simultaneously. Distance Education Council (DEC) has now allowed this.
A student can also pursue some other combinations including one Degree and Diploma/Post-Graduate Diploma/Certificate. Similarly, a student can also enrol for one Post-Graduate Diploma and one Diploma/Certificate, one Diploma and one Certificate, two Post-Graduate Diplomas, two Diplomas and two Certificate courses.
The following article appeared in the Hindustan Times on 21st July, 2017 may be perused:-
Beware! I question everything and everybody.