By taking loan from a bank, one has to pay interest. The person who takes and gives interest is cursed in hadith. Hence, after all it is unlawful and haram to take the interest. However, if someone is helpless in giving interest i.e. in the question mentioned above if there is only one way to save one’s lawful and halal income by taking loan from bank and there is no other way to save oneself from non-Islamic government tax,then for the sake of saving one’s halal income it is allowable to take loan only as much as needed.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband