OpenStreetMap statistics

Nodes, ways, and relations are relatively easy to count, you can simply use the India file from here http://download.geofabrik.de/asia/india.html and count the elements. Either use a sophisticated, osmium-based statistics program or simply

bzcat india-latest.osm.bz2 |
grep -E "<(node|way|relation)" |
cut -d\  -f1 | sort | uniq -c

Users are more difficult to count because the current data file does not list all users who are in India or whose centre of activity is India - it lists all users who are the last person to have edited an object in India, which likely includes tons of "drive-by mappers" and bots, and excludes those whose contributions have meanwhile been modified by others. Hence you will want to look at the history file for India for a more thorough analysis. It also depends on whether you only want to count active users or all users, and what your definition of an active user is!

Here are some ready-made pages with information about India:

• http://mapbox.github.io/osm-analysis-collab/users-by-country?yearIdx=11&minActiveDays=10&maxActiveDays=365&#2/22.0/28.0
• https://osmstats.neis-one.org/?item=countries&country=India

Since the above was written, a new command-line tool has made OSM data wrangling a bit easier for non-programmers. The osmium command-line program can convert an OSM PBF data file into an ASCII data format called "OPL" (short for object-per-line, meaning it has one line per OSM object). Once converted into this OPL format, standard command line tools can be used to process the data. For example, for a top-20 list of all users editing India, get the India history file from https://osm-internal.download.geofabrik.de/asia/india-internal.osh.pbf and then (all on one line):

osmium cat india-internal.osh.pbf -fopl | 
   cut -d\  -f7 | cut -c2- | sort | uniq -c |
   sort -rn | head -20

Insert "grep" commands at liberty to count just edits in certain years, and so on.

If you are comfortable with Python or C++, you can also use the pyosmium bindings to read the original .osm.pbf with Python, or libosmium to do so in C++.