Hello,

Your father can definitely try for graduation through open universities, there are various options regarding this, IGNOU is the biggest open university as it has regional centres all over India, and there are various study centres under each RC, also admission is open as of now till 31st January, if your father is interested, you can ask him to visit the official website of IGNOU and register at https://ignouadmission.samarth.edu.in/ .

Other than IGNOU there are various options such as DU SOL, Tamil Nadu Open University, Dr BR Ambedkar Open University, Andhra University, Netaji Subhash Open University, University of Mumbai to name a few, generally speaking there is no upper age limit regarding this.