Ruellia prostrata ?
SK434 17MAR-2017:ID : 5 posts by 2 authors. Attachments (4)
Location: AIT, Bangkok, Thailand
Date: 20 May 2016
Altitude:  40 ft.
Ruellia ... ???

I also think so. 
Which one ?
Pl. check if you can find match among Indian species as per comparative images at Ruellia
Appears close to images at Ruellia prostrata Poir., but may be some other species.
I guess it is matching as you have suggested.