Hi Nisha,

To crack DU JAT 2019 I would suggest you to prefer Arihant book. As it is one of the best publication for preparing any of the competitive exam. It will cost you under 400 rupees for the purchase. Also, you can prepare through online mock tests by joining online courses like Hitbullseye. It will cost you around 1300 for the complete online material. 

I hope I have cleared your doubt. Wish you good luck.