which itr form should i choose to file where income from commission is only source of income

what ITR form should i choose to file return for income is only from commission.

can i file itr 1 and put it in the coulumn
"income from other source" or choose ITR 3 ?

if i file in ITR 1 then can i claim expense on thet commission income.

intention to file for one reason that is full refund of money which has been duducted.

example: my income is 3,00,000
expense =50000
net income=250000.

now can i put it to other source in ITR 1 or have to file ITR 3 and claim expense.

please suggest ASAP.