Is it obligatory to pay zakat on money saved for a commercial project, upon which a year has passed, or should it be used to pay off part of the debts, knowing that the monthly income is not sufficient to meet needs and debts?

Zakat (definition) is obligatory on saved money if it reaches the nisab (definition), and its obligation is not waived because the money is saved for a specific purpose. As for debts, the more cautious view is that they are not deducted from the money subject to zakat. Rather, all the money is subject to zakat if it reaches the nisab and a full year has passed over it, even if its owner is in debt. This is the view preferred by some contemporary scholars.