Noc policy

Respected sir I am a regular employee of an autonomous organisation of central government I joined in Aug 2017 in the September of 2018 I have applied for another organizations for the same post then my competent authoritie said that NOC can not be issued for the same post . Ok I qualified the written examination and meanwhile some of my batchmate got NOC with the same . Then giving the reference of there NOC I again requested my competent authorities. Then they forwarded it to Regional Office giving the reference of applied not through proper channel and the R.O saying that your probation period is not complete so refused to provide NOC. Now I am finally selected in the next organization and my parent organisation is not accepting my resignation. They also saying that in future you may trouble for misleading the parent institution as you applied with out any information but I have informed them orally I don't have any proof for previous information but before the interview I have the receiving of my application for NOC but in that receiving it is mentioned that he applied directly. Sir is it true that I may suffer in future for my previous institution. But in my appointment letter it is mentioned that your job is temporary until your probation is cleared. Thanks and regards. Waiting for reply eagerly. Thanks