wi.firouter+adsl

hi friends , I am using a bsnl 's adsl modem on broadbañd connection from 2008. it is. a T-KD 318EUI and running flawlessly.now I want to share my bbnd conn. with my tablet,laptop and smartphones wirlessly.so I am bit confused in it, should I put forward a wi-fi router on my modem or I would...