Can we offset assets and liabilities or income and expenses?

No we cannot offset liabilites and assets as it would not present true and fair view. Offsetting would hide every relevant details. But yes in certain circumstances it has been allowed by Accounting standards to offset, but yet it recommends not to.

Under normal circumastances assets and liabilities can not be settoff against each other however under special circumstances certain assets can be settoff against certain liabilites. Such type of situation has been spread all over IFRSs. One of the  significant conditions for such settlement are:

• (1) The entity has a legally enforceable right of set-off'

• (2) there must be a simultaneous settlement criterion