The email Razorpay sends your customer confirms that money moved.
A Razorpay payment receipt is evidence of payment; a GST tax invoice is the legal document that creates your output liability and the customer's input tax credit.
Rule 46 lists the fields a tax invoice must carry, including a serial number, HSN or SAC, place of supply and the CGST, SGST or IGST split; a payment receipt carries almost none
Money received before supply needs a receipt voucher under Rule 50, and a tax invoice follows when the supply happens.
If you use Razorpay's own invoice or payment page product, you are still the issuer; check the output against Rule 46 rather than assuming the tool did.
No. The receipt confirms that a payment was captured and shows the payment id, amount and method.
The full guide has the formats, the deadlines and the worked examples.