Hello dear student,

As you said you want to give net in chemistry domain so dear student. When you will start to fill the form of net after the information they ask you and you feel it you need to upload few documents like ok first you have to upload your photograph in the format they asked for, then you need to upload your signature, then you have to to upload letter of recommendation from the university you are pursuing your degree this is only if you have not passed your degree yet. If you have already passed BTech or MSc or masters then you have to to upload your last semester's marksheet. As you said you belong from in OBC category so you also have to upload OBC category certificate in the given area.  Only these are the documents needed for net exam . I hope this was helpful to you.

Best wishes