I need the code for the radio cause i replaced the battery and now it won't work without the code

You may have entered the wrong code, disconnect the battery for a minute or so and try again.

If your radio is just saying "locked" without any numbers after it then just turn on ignition and turn radio on and leave until code appears..... Depending on how many wrong attempts have been made will depend on the wait! Could be minutes or hours...... Just turn on and wait!

It's a Mercedes, so electrical issues are extremely common. The ML especially of that year is about the most problematic car Mercedes ever produced.
It has issues everywhere from short circuits due to the wiring shrouding breaking down over time, to ECMs/ECUs failing without necessarily any good reason to. As there are too many faults on that particular vehicle to mention, it won't be easy to diagnose this one over the internet. You will likely require an auto electrician, and perhaps not even just one workshop to manage all types of issues. My best advice once you've dealt with this one and the vehicle is working is to sell it. You won't stop working on expensive issues with this mark and model.

Could be needing a security code. Did you look in your owners manual ??

Your radio is in theft lockout, you need the security code that came with the owners paperwork new.

you will have to go to the dealer to get the radio code as these are anti-theft radios so if they are stolen they won`t work without the code.

Well, I guess you won't be using the radio or driving after dark

You will get the code when you spend something,
because without the scan tool it won't happen.

Some radios hold the codes for a few Min's.However ,Disconnect the battery again and leave disconnected for an hour.Then reconnect and Enter codes and confirm.Should work ok.

Turn off the car and remove the negative battery cable off. let sit a few minutes then reconnect the cable. try it several times. The removal of the battery causes the computer to deprogram itself. what you will be doing is re-programming the computer module.