12 lac is the total foreseeable loss, however loss for current year will be .. Revenue recognised ( 67% of 85 lac i.e 56.95 lac) - Cost incurred to date (Rs.64.99) =804000 and expected loss to be recognised immediately will be 396000. OR you can also do as given in your book.
When the outcome of a construction contract can be estimated reliably, contract
revenue and contract costs associated with the construction contract shall be
recognised as revenue and expenses respectively by reference to the stage of
completion of the contract activity at the balance sheet date.
When the outcome of a construction contract cannot be estimated reliably: (a) revenue shall be recognised only to the extent of contract costs incurred that it is
probable will be recoverable; and
(b) contract costs shall be recognised as an expense in the period in which they are
incurred.
When it is probable that total contract costs will exceed total contract revenue, the
expected loss shall be recognised as an expense immediately.