Yes, Micromax Bharat 4 has a removable battery.
No. Micromax Bharat 4 does not have the gorilla glass protection but it does have the full lamination technology.
Yes, Micromax Bharat 4 does have the OTG support.
Yes, you can use it. But at any given time, one sim will work on 4G network and another will work in 3G network.
No. Micromax Bharat 4 does not have the hybrid sim slots. It has 2 dedicated sim slots and 1 dedicated MicroSD card slot.