We do not have a direct replacement for MB85RS2MTAPNF-G-BDERE1. The closest alternative that we can suggest is FM25V20A-G. It is a 2Mbit (256K x 8bit) SPI FRAM available in 8 pin SOIC package. Package dimension of these two devices are different. Please refer our datasheet for more information about our device. It is available at: https://www.cypress.com/file/141396/download .
Thanks and Regards,