Failing to apply through proper channel

Sir, I am a Central Govt employee in level -4. I have applied for the post of Assistant (level-6) in an autonomous body under Ministry of HRD without intimating my department. I have cleared the written test and just before the skill test I applied for NOC in my department asking for their forgiveness for my conduct for not intimating the department. But my department issued a memorandum under CCS conduct rule 3 (1) for Unbecoming a Govt. servant. Under these conditions please help me to get answers of my following questions:- 1. What will be penalty imposed on a Govt. employee who fails to intimate his department about his applying for another Govt. job? 2. Why cant my application for NOC after the written test result be treated as intimation, as i have intimated them before the declaration for final result? If not what is the Govt prescribed duration for intimation in such case? 3. How fair it is legally for a Govt. department to stop growth of its employee? 4. Kindly suggest in what way I should reply without making my case weaker in the near future in case I get selected in the final result of the department i applied into?