Srvice and pay protection

Sir, I am Dr.Narendra Prasad, working on the regular( permanent) post of Photographer( non teaching) for last 16 years at the same institution where from i have obtained my B.Sc.( Forestry) and MSc( Forestry) and Ph.D( Forestry) Mizoram Central University, Aizawl ( as in service candidate). After a long period in December 2020, my University( Birsa Agricultural University) advertised the post of Assistant Professor ( purely contractual for six months) on fixed salary of Rs 50000/- per month. I was also eligible for the advertised post so I also filled the form through proper channel and appeared in the interview for two departments like Natural Resource Management and Wildlife Sciences. I have been selected with first position in Department of Wildlife Sciences and 2nd position in NRM. Joining letter was issued to all except me because of unknown reasons. I consulted to our Vicechancellor to issue my joining letter and protect my present post and pay. But unfortunately, V.C. Said me to resign from your present post then join on the post of Assistant Professor, which is not possible because of heavy losses of salary 35000 per month and my Pension and GPF will be also lost immediately after resignation. Sir, I want the protection of my present service alongwith protection of pay & pay scale. If i continue on my present post, I will be retired in the age of 60 years, whenever the retirement age of Assistant Professor is 65 years. Sir please give me a legal advice so that I can join on the post of Assistant Professor without any loss. My remaining service is 4 years, if i continue with my present post.