Hi Vidya
Firstly, I'd use some high value treats. Show him the treats, and then click and treat. If he really isn't interested in the treats, then I would actually start when he was hungry - ie before a meal, or even skip a meal if necessary - so that food is uppermost in his mind. Click and give him a treat, repeat over and over, because what you are aiming for is for him to associate the click with being rewarded (ie treat). Do this for a few days and make sure he associates the click with treat before you start to use it in training.
The clicker is really just used as a marker, instead of praise. The advantages are that many people find it easier to get the timing right with a clicker.
A few tips that you may find useful. If he has been ignoring 'come' and you are going to reteach the recall, use a different word this time or even a whistle. Start off small (a few yards, in an area where he really has to come straight to you) and build up slowly to longer distances and with distractions.
The thing with recall is you need to make yourself the most interesting thing around, so that he wants to be with you.
regards
Jenny