Hi, I am Interior Designer and trunkey contractor. How should i create my Tax invoice and what is the percentage of GST is applicable.

I cannot maintain a log book. Also i provide service of making & installtion with providing different material such as providing upholstrey, furniture, glass work, electrical items, Steel work, Iron work etc.

It is not possible for me to put different tax slab on single project items.

So my question is how should i claim Tax from my customer.