Reasons include:
- Political and administrative consideration (Delhi and Chandigarh).
- Cultural distinctiveness (Puducherry and Dadra and Nagar Haveli and Daman and Diu).
- Strategic importance (Andaman and Nicobar Islands and Lakshadweep).
- Special treatment and care of backward and tribal people (Mizoram, Manipur, Tripura and Arunachal Pradesh, which later became states).