You need an embassy visa for Northern Mariana Islands if you have an Indian passport
Visa options for Northern Mariana Islands
Visitor visa
To visit the Northern Mariana Islands for Business or Tourism, you require a visa. A paper or embassy visa is the only type of visa available for visitors. Typically the visa is a stamp or sticker added to your passport. You must submit your application through the consulate or local visa center. Visit the government website for details.