I want to apply MRP as I am going to travel to Nepal in August. Does anyone know how long it will take to receive MRP?

Around three months

From the day I sent in the application until I got my MRP, about 2 months. Actually I am impressed this time.

At least 6 months, have you read old post on MRP.

Its little bit faster now days. DC takes around a month to post to Nepal, 8-9 days to reach nepal, in 10-15 days Nepal will post it back, then DC take around a month to post to u.

Sent app on nov 27, got back on dec 27 saying a4 don't work, resent it and now status says "document received".Getting close to 3 months already.

Looks like there is no hard and fast rule how long it ll take.

Mangale u sent back on end of dec, how its 4 months now ?
Now days its 3 months or less, have seen a couple of friends and mine too.
But make sure u print the form on right size, not only size of paper, but the borders too. Measure the borders and paper size as given on instruction. There are some tweaks like 100% document size and paper......something like that while printing. If u just print on A4 without tweaks, chances are it wont come out right. And if u send wrong sized form it will delay another month if they send back.
So the key is, it has to be A4 (ebay, amazon) not usual copy paper and print it with correct border sizes. Yes you can type on the form instead of writing with pen. 

@Bairaghi

I called Embassy and they recommended me to send prepaid envelop to them then they can send back actual form. He told me, many people get it wrong when they print from website just like you mentioned. So, to avoid delay, it is better to get the form directly from the Embassy.

It all depends.
Case one:I got my MRP after 5 months (app sent-->sep 13 2014, MRP received-->JAN5 2015, nothing in between).
Case two: My roommate sent it in June 2015..received back in Nov 2015.
Case three: Application sent nov 24, 2016---MRP not received yet..
last update-Feb 02/02/2016 MRP dispatched to embassy of Nepal, DC.
Now, I see they have started live enrollment. May be its quicker now.
Jaya MRP
Good luck

Dreambig
What do you mean by live enrollment? You mean you can apply online too?

http://www.nepalembassyusa.org/wp-content/uploads/2016/01/Press-Release_-Live-Enrollment-System-EONDC.pdf

Mine took approx 8 months.