How to get NOC if higher authority denied to issue it for appearing in interview for the same scale?

Dear Sir, I am working at an university (central govt) with grade pay level 10 for the last one and half year. Now due to my family reasons I had to apply to an another university but for the same grade pay (Level 10). Regarding this I asked for a NOC to my university which was rejected by the authority(higher level) and they straightly denied to issue the NOC. Although, I have sent an advance copy of my application to the future university but I need to produce it at the time of interview if I called for that. Now I have these questions: 1) Has the university any right to deny for giving a NOC to a permanent central government employee if s/he wants to move in other university? 2) My university will provide a intimation letter against my application that may state that "the NOC application was rejected" , If I get so, may I produce this letter at the time of interview ? 3)What legal steps I may take to get the NOC from my university? Even if I don't succeed in getting the NOC, how I can appear in the interview if called for? Thanks in advance