The stock tanked 5.73 per cent to end at Rs 78.10 on BSE. During the day, it dipped sharply by 10.92 per cent to Rs 73.80.
At NSE, shares of the company plunged 5.96 per cent to close at Rs 78.05.
The company's market valuation fell by Rs 77.49 crore to Rs 1,294.51 crore.
On the volume front, 24.34 lakh shares of the company were traded on BSE and over 78 lakh shares changed hands at NSE during the day.
"The CEO of NIIT Ltd, Rahul Keshav Patwardhan, has tendered his resignation due to compelling family reasons and has requested to be relieved from the close of business hours of July 31, 2017," NIIT said in a BSE filing on Friday.