What could be the Cipher String to add 3DES Cipher to SSL Profile ?

DES and 3DES comes under

BulkCrypto

and its already added with DEFAULT(NATIVE) cipher but you can't add

3DES

cipher alone. i believe, will come with the combination of example: RSA+3DES, ECDHE+3DES, etc.

Did you tried

DEFAULT:+3DES

?

Confirm the F5 version and purpose to use?