By Mukesh Sharma
BBC Hindi
Some nations have voiced concerns over potential attacks on their teams.
But Dr Gill told BBC Hindi security officials from more than 70 countries had declared their satisfaction with India's planning for the Games.
He said, "Security will not be just 100 but 120% foolproof. There will be around 100,000 security personnel to ensure safety during the Games."
Security in India has been under scrutiny since the terror attacks of March 2008 in Mumbai that left 101 people dead and 287 injured.
New Zealand recently said their team would only travel to Delhi if their government was satisfied that athletes would be safe to train and compete.
But Gill insisted that competitors should have no fears and said that he has issued guidance about spectators' movements.
He added: "I am warning the security agencies that these arrangements should not be an obstruction -there has to be a balance."
Gill also addressed health concerns about cases of the potentially-fatal dengue fever near the Games village in the Indian capital.
Dengue fever is a mosquito-borne disease that causes severe head, muscle and joint pains.
"The government is working on war footing [to tackle the problem] and no-one should be worried," he claimed.
Gill also said that allegations of corruption which have also plagued the delay-hit build-up to the Games were being fully investigated by India's financial authorities.
"The Prime Minister and the cabinet has always said that if at all there has been any misappropriation of funds then it would be properly dealt with."
The Commonwealth Games run from 3-14 October, with athletes are due to start arriving on 25 September.