Do I need a .bashrc or .bash_profile for MSI systems?

You will need both on MSI systems.

Most MSI systems, including HPC clusters: only $HOME/.bash_profile is sourced by default on login. To guarantee .bashrc is also sourced we recommend following this FAQ

Non-HPC systems (e.g., Lab workstations and queue,, etc): both $HOME/.bashrc and $HOME/.bash_profile are sourced on login.  See recommended setup methods below. 

Inside NICE sessions: Only $HOME/.bashrc is sourced by default. Again, follow the recommended solution below to merge old .bashrc and .bash_profile files into one .bashrc.

Recommended .bashrc and .bash_profile Setup

Refer to these FAQs to update your .bashrc, and then your .bash_profile.