Hi @Hifni Nazeer ,
Welcome to Microsoft Q&A forum and thanks for using Azure services.
As I understand from the question, you want to understand the cost during SQL Failover.
Secondary active geo-replication databases are priced at 100 percent of primary database prices. The cost of geo-replication traffic between the primary and the online secondary is included in the cost of the online secondary.
Reference: Geo Replication Cost
Hope this helps. Please let us know your inputs for more queries.