Legal advice for large crypto holder

Dear experts,

I own a very large amount of cryptocurrencies. I worked for cryptocurrencies a few years ago and heavily dabbled in ICOs, NFTs and DeFi.

I have only partial records here and there. There are tens of thousands of transactions. The websites I used are not there now.

I never sold or bought cryptocurrencies with rupees.

I want to pay taxes, but I don't want to risk my life. What should I do?