HOD of Central Govt not issuing NOC

Sir, I have joining an Autonomous central govt organisation 1 month ago. I am on probation period of 2 years. I am filling new govt. Job form for higher pay scale. My organisation have not provided permission to attend an interview in past stating public interest. Now I am doubtful about intimating them about new Govt job form that I am filling. If I do not tell them then I won't get NOC to attend interview technically. If I tell them then they will release a Office memorandum like previous that I am not allow to attend exam or interview stating public interest. So I want suggestions regarding follow. - 1. Should I intimate them or not? 2. Should I fill my current govt job detail while filling new examination form.? Can I skip it to avoid NOC? Is there any legal consequences of hiding this fact even if I don't want any benefit from that organisation. 2. Can new govt job accept my resignation from previous organisation instead of NOC? (I do not want any benefit from previous organisation) Thank you in advance.