Is requirement of ITR of last 3 years for Arms Licence legal

Dear learned friends, I was browsing the Delhi Police Website as well as the website of Gujarat State Police and police department of many other states, I came to know that now licensing authorities have started asking for the income Tax Returns filed in recently passed 3 years. While going through the Arms Act of India 1959 and Arms rule 1962, I didn't found any such requirement. Also in my humble opinion right to defend onsleves life and property is granted by article 19 of the Indian Constitution and the soul of RKBA is hidden in Article 21 of India, asking for ITRs of past years is something like biasing people on the basis of their economic and financial condition. What is the purpose of asking to submit ITRs of past and current years? If it's to know the financial.condition of the applicant and consider it as one of the criteria for the grant of licence, it's against the soul of right to equality and right to justice without being biased on the basis of race, cast, creed, religion, s*x, ethnicity and not the least on oneself's economic condition.