Property now open. Category 5. Has an exec lounge. Doesn't say if it's open on weekends, but my guess is that it is open since it's a JW & it's in India.
http://news.marriott.com/2015/04/mum...-property.html
Property website:
http://www.marriott.com/hotels/trave...-mumbai-sahar/
Cheers.