There are many exchanges that sell and buy NIM. Compare the options and find the one that suits you best.
KuCoin is a popular exchange amongst traders, with live support and mobile apps.
HitBTC is one of the oldest exchanges.
Changelly is a non-custodial facilitator between exchanges and traders.
Bitladon is focused on the European market and accepts credit card payment.
Changehero is a beginner friendly exchange without login.
BTC-Alpha is an exchange for traders with over 100 coins.
CoinSwitch allows Crypto-Crypto exchange with an easy-to-use interface.
CoinDCX is an advocate for cryptocurrencies in India, its origin.
Swapzone finds, aggregates and indicates exchange deals on the crypto market.
SwapSpace is an instant aggregator of cryptocurrency exchanges.