I have a date format in the form dd.mm.yyyy
Assuming that you mean a DATE data type then, no, you don't have it in the format dd.mm.yyyy. A DATE data type value is stored within the database as a binary value in 7-bytes (representing century, year-of-century, month, day, hour, minute and second) and this has no format.
I want to convert it mm/dd/yyyy. Is it possible?
No, because DATE data types do not have a format.
However, what you probably meant to ask is:
I want to convert display as it mm/dd/yyyy. Is it possible?
Yes, use TO_CHAR with the appropriate format models:
SELECT TO_CHAR( date_value, 'mm/dd/yyyy' )
FROM table_name
If you mean that you have a CHAR or VARCHAR2 data type storing date values in the format dd.mm.yyyy then use TO_DATE to convert it to a DATE data type and then TO_CHAR to display it to the format you want.
SELECT TO_CHAR( TO_DATE( string_value, 'dd.mm.yyyy' ), 'mm/dd/yyyy' )
FROM table_name