Section 11 in The Digital Signature (End entity) Rules, 2015 [Entire Act]
Reference element Digest
SHA256 FIPS 180-4
Signature Algorithm
SHA256 with RSA PKCS-1 Version 1.5
o Exclusive (without comments), XML-EXC-C14N ... issued as per interoperability guidelines
Public Key Algorithms
RSA PKCS-1 Version 1.5
ECC curve
NIST P-256, P-384, or P-521
Long Term