Option 1: Goa and Maharashtra. This option is incorrect as Palghat does not join these two states.
Option 2: Kerala and Karnataka. This option is incorrect as Palghat does not join these two states.
Option 3: Tamil Nadu and Kerala. This is the correct answer. Palghat is a city located in the Palghat Gap, which acts as a natural gateway between the states of Tamil Nadu and Kerala. It is situated near the border of these two states and serves as an important transportation hub between them.
Option 4: Mizoram and Manipur. This option is incorrect as Palghat is not located in either Mizoram or Manipur.
Therefore, the correct answer is option 3: Tamil Nadu and Kerala.