The primary mode of transportation within Mizoram is:

Railways
Air travel
Road transport
Waterways

The primary mode of transportation within Mizoram is road transport. This is because Mizoram is a landlocked state with no major rivers or coastlines. The state has a well-developed road network that connects all major towns and villages. Road transport is also the most affordable and convenient mode of transportation in Mizoram.

Railways are not a major mode of transportation in Mizoram. The only railway line in the state connects Bairabi in Mizoram to Silchar in Assam. This line is not very well-developed and is not used by many people.

Air travel is also not a major mode of transportation in Mizoram. The only airport in the state is Lengpui Airport, which is located in Aizawl. This airport is not very well-connected to other parts of the country and is not used by many people.

Waterways are not a major mode of transportation in Mizoram. The state has no major rivers or coastlines. The only waterways in the state are a few small rivers that are not used for transportation.

Therefore, the primary mode of transportation within Mizoram is road transport.