Union Territories & Panchayats
(1) Municipality seats are generally filled by direct election from territorial constituencies called "wards". (2) State law may also provide for representation (usually non-voting) of people with special municipal-administration expertise, local MPs/MLAs/MLCs, and Wards Committee Chairpersons, plus the method for electing the Municipality's own Chairperson.
This mirrors Article 243C (Panchayat composition) for urban local government: municipal councillors are directly elected from local wards, with some room for additional non-voting expert representation and coordination with local legislators.
This is why a city's Municipal Corporation is made up mainly of directly-elected ward councillors, with the corporation's Mayor or Chairperson chosen according to whatever method the relevant state law specifies.