Dual

Only BITSAT score is the way out:
http://www.bitsadmission.com/Eligibility_Criteria.aspx: Eligibility criteria
http://bitsadmission.com/cutoffscores.aspx:cut-off scores 2016

Actually, both of them have a great brand name, Symbiosis and NMIMS both will give you great course and brand value but I would recommend you to go for NMIMS just because it's in Mumbai which will give you great job opportunities compared to Pune.

Following space crunch on the campus, IIEST (Indian Institute of Engineering Science and Technology), Shibpur has decided to scrap its five-year integrated dual-degree(B.Tech and M.Tech) programme from the academic session 2017-18. Discontinuing the programme, the institute will bring back its BTech programme after three years. Till date, the institute has admitted around 650 students - every year - to its dual degree programme.

Good morning,
Look, university courses are affiliated with the respective university itself.
There is no question of AICTE coming in between.
The courses in Hyderabad University are affiliated by Hyderabad University itself. and all those courses have very high weightage and value.
Thanks!

You'll usually need an HNC, HND, foundation degree, or degree in aerospace engineering, avionics, or a related subject, like:
Electrical or electronic engineering.
Mechanical engineering.
Manufacturing or product engineering.
Physics or applied physics.
Software engineering or mathematics.
All the best.

Yes, you can pursue one regular and one distance degree at the same time. However, pursuing two regular or two distance degree is not possible as one of the degrees will not be taken into consideration.