If you mean database PL/SQL then I don't think that it is possible.
If it is done from a form or library then it might be possible.
What is the caller program of the PL/SQL code.
I believe you are asking how to call a custom form from seeded or another form using PLSQL block. You can use CALL_FORM, OPEN_FORM or NEW_FORM procedure to call another form. Use form help to get more detail about these procedures
no Amit, I'm asking how to call custom form from data base procedure.
This is not possible based on your requirement.
Agree with Bashar