Vijayraghavan is presently Secretary, Department of Biotechnology.
He will hold the additional charge for three months beyond July 31, 2015 or until the appointment of a regular incumbent, an order issued by Department of Personnel and Training (DoPT) said.
The DSIR, under the Ministry of Science and Technology, is mandated to promote industrial research for indigenous technology promotion, its development, utilisation and transfer.
The post has been lying vacant for over one year.
Vijayraghavan was in May last year given the additional charge of Secretary, DSIR for three months. He has been getting regular extension for the post since then.