As @Unknown stated in the @Dakiraun’s request, there are 2 different models named “Mega”…
meliusltexx (aka GT-I9200/9205)
https://github.com/search?q=meliusltexx&type=repositories&s=updated
https://sourceforge.net/projects/samsungmega6-3/
crater (aka GT-I9512)
https://github.com/search?q=samsung+crater&type=repositories&s=updated
Community
https://forum.xda-developers.com/f/samsung-galaxy-mega.2351/