make shift+4 key produce rupee symbol instead of dollar symbol

I don't know for sure if this will help - but - have you investigated the built in keyboard lay out settings?

System settings => keyboard layout

Hello, Enrico and Stretch,

I couldn't find 'system parameter settings' anywhere, but when I went to System Settings > Keyboard, I couldn't find the disposition panel.

I got two tabs on top, Typing and Shortcuts. I also had an option below, Layout Settings. I added 'English, India (with Rupee Symbol)'. And when I went to Keyboard Layout Options for this keyboard option, I had the choice of adding the rupee currency symbol 'on 4', as it said.

Now, when I open the keyboard layout chart, I can see the 4 key has two options, dollar sign on top, and rupee sign next to 4. But when I type shift+4, I still get the dollar sign. How do I get the rupee sign?

Sorry, I meant to say that the shift+4 key produces no results - neither the dollar nor the rupee sign.

Sorry I don't have the menus in English, I have to guess the words. "disposition" was wrong...

I think you found the correct place, saying: "I also had an option below, Layout Settings."
There you have 4 tabs, am I correct? There, on the third tab, you have also a "Settings"
button, in the right bottom corner? There you have a full list of options (16 of them),
and the second one concerns the monetary signs.

This would be the solution for having "Alt Gr" 4 (not shift-4)

Hello Enrico,

Thank you for being so prompt. :)

When I scrolled down the Layout Settings menu, I realised I hadn't selected which key would activate the 3rd option. I chose the Alt key. Now when I press Alt+4, it gives me the beautiful rupee symbol! Thank you so, so much. )

Thanks Enrico Rosina, that solved my question.