What Tag/Memo should I specify when transferring XRP/XLM/ATOM/TON/LUNA/LUNC to Tangem Wallet?

Destination tag/Memo/Message is an additional address value in numeric and/or string form. It allows identifying the recipient of an XRP/XLM/ATOM/TON/LUNA/LUNC transfer on a centralized exchange (e.g., Binance, Coinbase).
You do not need to specify a destination tag when sending XRP/XLM/ATOM/TON/LUNA/LUNC coins from an exchange to Tangem Wallet. Since you are the one in control of this address, the coins will automatically appear in your Tangem Wallet.
That said, some exchanges still offer to specify a tag when withdrawing coins. In this case, you can specify any value of the tag — for example, any number or digit. None of these numbers are needed to get your coins.