Is it true that if you drink 3 litres of sulphuric acid, you become immune to it?

no you will die sulphuric acid burns you almost everything that starts with acid can burn you. Anything with a pH of 6.9 or lower can burn like for example sulphuric acid a 3.6 to a 5.6 can burn you or go through you. Remeber anything that has a base of 8 to 14 that max of a pH scale is a base. remeber some base is not harmful which is soap detergent and other things ( Do Consume these things). Anything near 7 of a pH scale cannot burn you its is because it is neatural for example water H2O Hydrogen 2 Oxygen.