This is an excerpt from the latest unlockdown (Unlock 2.0) guidelines from the Ministry of Home Affairs,
States/UTs, based on their assessment of the situation, may prohibit certain activities outside the Containment zones, or impose such restrictions as deemed necessary.
However, there shall be no restriction in inter-State and intra-State movement of persons and goods including those for cross land-border trade under Treaties with neighbouring countries. No separate permission/ approval/ e-permit will be required for such movements.
The full document is available here
Now, due to rise in COVID-19 cases, many states like Tamil Nadu, Karnataka, Maharashtra etc. have imposed travel restrictions for movement of persons as of today through state and sometimes district borders. Persons have to go through an online process of obtaining e-passess for travel.
My understanding is that the states must strictly follow these guidelines and that means they cannot impose such travel restrictions (note the however in the second paragraph of the excerpt).
I would like to know if these restrictions are legal given the central guidelines and if so under what act/law?