The three permits, plainly
Protected Area Permit (PAP) — issued under the Foreigners (Protected Areas) Order, 1958. Required for foreign nationals visiting Arunachal Pradesh, Nagaland, Mizoram and Manipur, plus parts of Himachal Pradesh, Jammu & Kashmir and Rajasthan. Issued by the Ministry of Home Affairs or by the state government on MHA's behalf, almost always via a registered tour operator.
Restricted Area Permit (RAP) — issued under the Foreigners (Restricted Areas) Order, 1963. Required for Sikkim and certain Himalayan border zones, and historically for the Andaman & Nicobar Islands (mostly waived since 2018). Issued by Indian missions abroad with your visa, at FRROs, or at the Rangpo/Bagdogra entry points for Sikkim.
Inner Line Permit (ILP) — a colonial-era permit (Bengal Eastern Frontier Regulation, 1873) that applies to Indian citizens only, currently enforced in Arunachal Pradesh, Nagaland, Mizoram, Manipur and parts of Lakshadweep. Foreigners do not use the ILP — your PAP covers the same access.
