Source document: https://docs-lawep.s3.us-east-2.amazonaws.com/1697803162776.pdf (India)
VOLUNTARY RETIREMENT Government servants may retire from service voluntarily with pensionary benefits before attaining the age of superannuation under the following provisions of Fundamental Rules and CCS (Pension) Rules, 1972.

FR 56 (k) FR 56(m) Pension Rule Group ‘C’ Officer not governed by pension rules any 48 (1) (a) All Government servants covered CCS (Pension) Rules, 1972 by 1 Eligibility Group ‘A & B’ officers: i.

Entered service before 35 years of age ii.
Attained 50 years of age Other cases: Pension Rule 48 (A) All Government servants covered by CCS (Pension) Rules, 1972 55 Attained years of age None 2 3 4 Minimum service Notice period Acceptance Automatic, 3 months 30 years 30 years 20 years 3 months 3 months 3 months if non- acceptance not conveyed before expiry of notice period Not required Automatic, if non- acceptance not conveyed before expiry of notice period Acceptance required but acceptance presumed if non- acceptance not conveyed before expiry of notice period Any ground 5 Grounds for non acceptance Suspension None Suspension It may be seen that a notice of voluntary retirement under FR 56(k) 2. or Rule 48 (1)(a) of Pension Rules does not require acceptance.
It is only in the case of a government servant under suspension that the appropriate authority may withhold permission to retire under these rules.

This is unlike the notice under Rule 48(A) of Pension rules which requires acceptance by the appointing authority.

In case of notice under FR 56 (m) even the right to refuse if the government servant is under suspension, is not available to the Government.
(The Rules mentioned above are available in the relevant Rules Book viz., FR&SR Compilation and CCS(Pension) Rules, 1972).

In addition to the above, permanent employees declared surplus in any Ministry / Department may opt for Special Voluntary Retirement Scheme.

Detailed guidelines for this purpose have been issued by DoPT vide O.M.No.
25013/6/2001-Estt (A) dated 28th February, 2002. persmin.nic.in > OM & Orders > Establishment [O.M.No.25013/6/2001-Estt (A) dated 28.2.2002] AIS Officers: Voluntary retirement of AIS officers are regulated by Rule 16(2) of AIS (DCRB) Rules, 1958.