Hello Nirban,
By default, showing ribbon prevents showing backbone atoms.

To allow showing backbone atoms at the same time as the ribbon, just use command "ribbackbone". 
<https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/ribbackbone.html>

You can still show/hide the atoms as you wish (display and ~display), so you can display only the backbone atoms you want and hide the others.

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On May 28, 2021, at 10:41 AM, Nirban Dey <nirbandey95@gmail.com> wrote:
>
> Hello,
> I am a Masters student in India currently using chimera for my thesis. I am facing a problem. I have attached a state file of my docked complex. There some residues 251, 245, 243 formed H bonds with the ligand through the O atom. I am not able to display the residue clearly. O atom is looking like a dot. I want to show the residue clearly making bonds with the ligand without hiding the ribbon like the residue 247. Those residues are clearly visible only if I hide ribbons for that residue. Kindly  help me to show the residue properly without hiding their ribbon.
> Regards
> Nirban
> <final.pyc>