(Ok, so looks like they updated the website in the last few days. Few days back, I had seen the 3series and 4series bikes @ RR Madivala, but didn't see them listed on the site.)
I did a few quick checks of the Montra3.2D, vs Trek3700D (specs listed currently on the Trek website) --
* I don't know how to compare frames, but (FWIW) the shape of the bottom tube for the Montra seems similar to the Trek.
* The fork -- they are both 100mm, but don't know if the Montra one is coil springs (similar to the Trek).
* The derailleurs -- Montra is Altus+Acera, while Trek is Altus+Altus. (I see the Trek 3900D has Altus+Acera.)
* Rims -- dunno how to compare.
* Hubs -- The Trek site doesn't seem to list those; the Montra one says Shimano Deore, which I think are quite good (I have Deore XT on my Surly).
Since the Montra bikes save a bit on duty, and the Trek 3700 (non-Disc) is priced ~Rs27K (IIRC), I'd say the Montra 3.2D is probably better than the Trek3700; maybe closer to Trek 3900D; not sure what the Rs price is, for the Trek3900D.
(Aside -- I looked at the specs of Montra 4.2HD, and compared them with the Trek4300D; the derailleurs on the Montra are Acera+Alivio; on the Trek, Acera+Acera. Montra is better on that count.)
-{db}.