He was 85 and is survived by a son and daughter, according to Pondicherry University sources.
His wife predeceased him, in 2009.
Gnanam was the second Vice-Chancellor of Pondicherry University from 1991 to 2007. He headed the National Assessment and Accreditation Council.
He had also served as Vice-Chancellor of the Bharathidasan University, Tiruchirapalli and Madras University.
He was associated with various policy-making bodies and institutions on higher education.
Gnanam is said to have been instrumental in the establishment of the community college attached to Pondicherry University during his tenure as Vice-Chancellor.
A meeting to condole his death was held at the university premises today.