Unrecorded liabilities when paid are shown in:

Debit side of Realisation Account

The correct answer is option 1- Debit side of Realisation Account.

Unrecorded liabilities when paid are shown on the Debit side of Realisation Account.

Unrecorded liabilities are those liabilities which are not recorded in the books of account. The accounting treatment when the unrecorded liability is paid off:
Realisation A/c Dr.
      To Bank A/c