I am working on PM, on which each form has 60 fields and on each field validatio

What form are you using - Portal, Tempo (non SAIL) or SAIL?

too much java script and image in form make it heavy to load. Suggested to use Sail Form with apian 7.4. otherwise use JS file for the validation and minimize the Java script in form.

@malathik : Tempo (Non SAIL)

Ideally, you should consider breaking such complex forms in to reasonable chunks. First of all, are all the users going to fill in all the 60 fields in the form? Are there any form level grouping (for e.g. if I select Car insurance, do I need to see sections that talk about Personal insurance etc..)
With that said, once you work out the structure, break your form into series of forms that the user can fill out and connect them via Activity Chaining. This would greatly enhance the user experience. In addition, you can build logic between the chain to decide what content within the next form should be displayed, further making the experience for the user intuitive and easy.
Activity chaining allows users to navigate forward as well as back should they wish to step back.

Since you have the form already, the best way to architect the change is to copy for form and remove the fields that are not applicable for the form. This will avoid you from redesigning the entire form again.