Appraisal Band

I worked for one unit for the past 9 months and now currently allocated to another project in a different unit. I raised two Project end appraisal. I was thinking that my Band will be initiated from the last project where I spent 9 months but my current supervisor says, they'll provide me with an appraisal band. I have a concern as to how they're going to judge me based on one month's work. I also checked with HR as well but she said she'll check with TMO.

I have a feeling that I'm going to get "c"band as I've just joined this project and my current supervisor also said I'm not going to assure you about the band as it comes from higher level and since you've just spent 1 month here, there's chance that you might not get good band as management will focus on employees who have spent good number of months and contributed for unit growth.

I wanted to know do we have the option to reject the band incase I gtet "c" band? What other options do I have?