There is insufficient evidence available to accurately verify the claim.
The book quoted Nehru saying that their policy was ahimsa(non-violence), and they wanted to scrap the Army as the police were good enough to meet the security needs of the country.
Further to this, a dissertation published by the Univerity of Vermont mentions that Nehru believed that relying on Indian defense forces was unrealistic and advocated a reduction of the Indian Army. It cited A A Rudra serving as a senior staff officer recounting his experience when he met Nehru, who dismissed the Army's request and told to 'Scrap the Army.'
However, it also said that it is not known what transpired between Lockhart and Nehru during the meeting, and the story has been repeated many times.