According to Official Guinness Records,
The longest individual net session by a male is 50 hr 4 mins 51 sec, achieved by Virag Mare (India) in Pune, Maharashtra, India, from 22 to 24 December 2015. Virag played against both actual bowlers and a bowling machine during this attempt.
For a complete list of 2015 records, please visit 2015 Guinness Records in India.