Customised user registration / sign-up forms in Drupal 7 I want to have 2 customised registration/sign-up form for different users with different fields for their account and profile (like buyer and supplier). How to make different form or multi step form for each kind of user based on role. 

How can it be accomplish? Please help in this regard. As after lot of search, i could not figure it out. Is there better approach which is being used then please let me know.
When you need different set of fields for different users you should have a look at the profiles 2 module. There's a good chance that you can acomplish your requirements without any coding.

BTW: This kind of question has been asked many times here. The search functionality will give you a lot of information about this topic.