How do I request and receive user input in a .bat and use it to run a certain program?

If the input is, say, N, your IF lines evaluate like this:

If N=="y" goto yes 
If N=="n" goto no
…

That is, you are comparing N with "y", then "n" etc. including "N". You are never going to get a match unless the user somehow decides to input "N" or "y" (i.e. either of the four characters, but enclosed in double quotes).

So you need either to remove " from around y, n, Y and N or put them around %INPUT% in your conditional statements. I would recommend the latter, because that way you would be escaping at least some of the characters that have special meaning in batch scripts (if the user managed to type them in). So, this is what you should get:

If "%INPUT%"=="y" goto yes 
If "%INPUT%"=="n" goto no
If "%INPUT%"=="Y" goto yes
If "%INPUT%"=="N" goto no

By the way, you could reduce the number of conditions by applying the /I switch to the IF statement, like this:

If /I "%INPUT%"=="y" goto yes 
If /I "%INPUT%"=="n" goto no

The /I switch makes the comparisons case-insensitive, and so you don't need separate checks for different-case strings.

One other issue is that, after the development mode command is executed, there's no jumping over the other command, and so, if the user agrees to run Java in the development mode, he'll get it run both in the development mode and the non-development mode. So maybe you need to add something like this to your script:

...
:yes
java -jar lib/RSBot-4030.jar -dev
echo Starting RSbot in developer mode
goto cont
:no
java -jar lib/RSBot-4030.jar
echo Starting RSbot in regular mode
:cont
pause

Finally, to address the issue of processing incorrect input, you could simply add another (unconditional) goto command just after the conditional statements, just before the yes label, namely goto Ask, to return to the beginning of your script where the prompt is displayed and the input is requested, or you could also add another ECHO command before the jump, explaining that the input was incorrect, something like this:

@echo off
:Ask
echo Would you like to use developer mode?(Y/N)
set INPUT=
set /P INPUT=Type input: %=%
If /I "%INPUT%"=="y" goto yes 
If /I "%INPUT%"=="n" goto no
echo Incorrect input & goto Ask
:yes
...

---

Note: Some of the issues mentioned here have also been addressed by @xmjx in their answer, which I fully acknowledge.

i just do :

set /p input= yes or no
if %input%==yes echo you clicked yes
if %input%==no echo you clicked no
pause

Here is a working example:

@echo off
:ask
@echo echo Would you like to use developer mode?(Y/N)
set INPUT=
set /P INPUT=Type input: %=%
If /I "%INPUT%"=="y" goto yes 
If /I "%INPUT%"=="n" goto no
goto ask
:yes
@echo you select yes
goto exit
:no
@echo you select no
goto exit
:exit
@pause