Agile Form for Company Registration

It requires service classification code (SAC) , according to your screenshot you should enter the code in details of services supplied by the business

I had tried to enter SAC code, but the system is not accepting it. When I click on prefill, the message pops up as invalid code. 

 

Then u must confirm the code in relation to services the company wants to provide

I've not gone through form, But there may be any radio button, which is asking that Proposed registration is for good or services or both & may that you have selected Goods & services both/ Nature of business , So recheck it without generating PDF, If it's not the case the Registration is optional for gst or else can raise ticket to MCA.