Static outbound IPs are assigned as a fixed set of 3 per service for high availability, and there is no option to reduce that number. Traffic is load-balanced across all 3 IPs, so all 3 must be whitelisted on the downstream service. You would need to check with Dhan about increasing their IP whitelist allowance to accommodate all 3.

Can I rollback to Rollback to Standard Static IPs which will provide one IP right? Can we use it as whitelist IP at Dhan side?

New static IP enablements always assign 3 IPs, and there is no rollback to a single-IP configuration. Disabling and re-enabling static IPs would also assign a fresh set of 3 IPs. Since Dhan only allows 2 whitelisted IPs and all 3 must be whitelisted for reliable traffic, your best path is to ask Dhan to increase their whitelist allowance to 3.

I'm facing the same issue. In my case I need to have a single IP or the legacy API that I am using will not work.

I need to be fixed very soon or I will have no choice but to leave Railway

Or is there a way I can revert to single IP? This is very urgent for my business.

Railway API team told, there is no way for single IP.

I already moved out of the railway.