Realisation A/c is debited with __________ on the dissolution of firm.

During dissolution, the values of all existing realisable assets are closed by transferring them to the debit side of the Realisation Account via the entry:
$$\text{Realisation A/c Dr.}$$
$$\text{To Sundry Assets A/c}$$
External liabilities, cash realizations, and partner takeovers are credited to the Realisation Account.