Q:

keyboard shortcut for mouse right click

What combination of keys produce a right-click and a left-click?

A:

There isn't one for left-click, though spacebar and Enter are often usable.
Right-clicking is usually a request for a context-sensitive menu which is performed on the keyboard either by typing

≣ Menu key (https://en.wikipedia.org/wiki/Menu_key), 
Shift+F10, 
or sometimes Ctrl+Shift+F10.

About 65% of applications out there won't respond to the keyboard request for a context menu, because Windows programmers typically code WM_RBUTTONUP rather than the correct WM_CONTEXTMENU.  Coding the latter allows for the correct action in response to the keyboard.

A:

You can define your own using software like autohotkey:
Example
This code replaces:

left alt to left mouse click
right alt to right mouse click

Code:
LAlt::LButto
RAlt::RButton

Link to autohotkey keyboard remapping: link
Link to autohotkey download : link

