The client receives income as a beneficiary of family trust and he is eligible to claim Small Business income tax offset of $1000 in his individual tax return.

There is no option I can see to claim the small business income tax offset in the trust distributions section, but it's available only in in sole trader business schedule.

What is the process to follow in order to claim this offset if an individual receives income as a beneficiary of a family trust?

Make sure to activate "Trust" via ITR

Select "Income > Trust" , then Add or Select a "Worksheet"

Fill the "Share of 'net small business income' less deductions attributable to that share" and in "Estimate" tab you will find the calculation: