The 1980-batch Assam-Meghalaya cadre officer was accorded a guard of honour before he took charge at the 'black cat' commandos' headquarters here.
Tayal was till now serving as the Special Director General in paramilitary CRPF and was heading its formation in Jammu and Kashmir.
He is expected to serve in the top post till August next year when he is scheduled for superannuation.
The post fell vacant after incumbent chief J N Choudhury retired on May 31.
NSG was raised in 1984 as a federal contingency force with a specific aim to undertake counter-terror and counter-hijack operations and it was later tasked to protect high-risk VVIPs.