Madurai-based Thangamayil Jewellery Ltd has made a profit after tax of Rs 7.93 crore (Rs 3.74 crore) in the previous year, registering an increase of 112 per cent in the fourth quarter. Sales increased to Rs 187.46 crore (Rs 111.50 crore), registering 68 per cent growth. The net profit margin increased to 4.23 per cent (3.35 per cent), due to better price realisation.