Thought I would add to this as I am using Resolve 16 Beta.
To render a section of your timeline only (Video, Sound, Fusion Component, image etc)
1. Select the Delivery tab from the bottom ribbon strip.
2. Select the section of the timeline you want to render using the orange slider in your timeline. (The drag handles are at either end of it).
3. Select Single Clip from the Render settings box (Top left)
4. ...and then add to render queue and render
To render only an individual clip from a section of your timeline
1. Select the Delivery tab from the bottom ribbon strip.
2. Select the section of the timeline you want to render using the orange slider in your timeline. (The drag handles are at either end of it).
3. Select the individual clip you want to render. (So it is highlighted red)
4. Select Individual Clip from the Render Settings box (Top Left)
5.......and then add to render queue and render
Sorry if my terminology isn't correct but I think you'll get what I mean.....