Is National Institute Of Management (NIM) a valid university & can do graduation & MBA as it is not UGC recorgnised

I have done MBA from NIMS and suddenly during a job i am informed that my degree is fake as NIMS in not valid. However I did not loose my job as they find i am the one who is cheated. But i can not use these certificate in future....

I was a student of National institute of management and i successfully completed my MBA.After that i got a job in Larsen and Tubro Ltd as a marketing manager..so i proudly says to all my friends that if you want to do any course kindly go in NIM.