Formal:
* നീ എപ്പോൾ വരും? (Nee eppol varum?) - This is the most direct and formal way to ask.
* നിങ്ങൾ എപ്പോൾ വരും? (Ningal eppol varum?) - This is also formal, but slightly more polite.
Informal:
* എപ്പോൾ വരും? (Eppol varum?) - This is informal and assumes a close relationship with the person you are asking.
* എപ്പോഴാ വരുന്നത്? (Eppolaa varunnathu?) - This is a bit more casual and means "When are you coming?"
Other options:
* നീ വരുന്നത് എപ്പോഴാ? (Nee varunnathu eppolaa?) - This is a bit more casual and means "When are you coming?"
* നീ വരുമ്പോൾ പറയുമോ? (Nee varumbol parayumo?) - This means "Will you let me know when you are coming?"
The best way to ask depends on the context and your relationship with the person.