Relations Between Union and States
(1) Notwithstanding Articles 246 and 254, both Parliament and every State Legislature have power to make GST laws. (2) Parliament has exclusive power over inter-State GST (where the supply crosses state lines).
Added by the 101st Amendment (2016) that introduced the Goods and Services Tax, this article specifically overrides the normal Union/State/Concurrent List division to give both the Centre and every state concurrent power to legislate on GST - a genuinely new kind of shared taxing power specifically carved out for this unified indirect tax reform.
This is the constitutional basis for India's GST system, under which both the central government (through CGST) and state governments (through SGST) levy their own components of a single, largely-unified tax on goods and services.