NoC from Current Employer

I am working with one of the IIM which is an autonomous body. I have few queries as below: I have applied for another autonomous body [IISER] wherein I have given an undertaking stating "at the time of interview, I will be submitting NoC from my current organization" a) The organization where I have applied is organizing written test as Part A, Pre Screening and Part B as Screening test followed by interview only for the qualified persons in Part B test. The Organization has asked to submit the NoC from current employer, in absence of the same, they wont allow for pre-screening test also. Query: a) I am not willing to obtain the NoC as of now, as in case I am unable to qualify the Part A, Pre-Screening test or Part B Screening test my NoC will be wasted. b) In case, I am able to clear all the tests Part A and Part B along with the Interview, can I join without submitting my NoC and giving an undertaking as I do not wish any benefits from my present employer? Kindly advise, in a year only four NoCs we can avail and for just the purpose of entrance test, we cannot waste the NoC.