Switch to particular user from root account and type the following to see current limits of that user

ulimit -a  — show all limits
ulimit -u  — Max User files
ulimit -s  — Stack Size
ulimit -i   — Pending signals
ulimit -p  — Max process allowed

Edit /etc/security/limits.conf and add soft and hard limit for user shell limits:

To change the “soft” and “hard” limits for the maximum number of

user1              soft     nproc           2000
user1              hard    nproc           8000

For Global Change, 

Edit the file  /etc/bash.bashrc.local
Use “if” statment to explicit for particular user.