If you are not able to download the admit card then you should check proper site for that particular exam. Downloading admit card from mobile will be not that helpful. You should be able to take out the print easily. Or every exam's official site gives an email about admit cards then you can check on that aslo.

All the best.

What exactly do you want to know? 

Yes you need to download your admit card on your laptop, preferably, and it will always get downloaded in pdf format. Then get a print out of the same. Suitably, take 2-3 copies of the admit card. 

Carry 2 copies of your admit card, a valid I'd proof (passport, voter I'd card, driving licence, etc.) and the required stationery items. 

Reach the exam centre on time!! 

All the best!!