TAXES - Income (Loss) Before Provision for Income Taxes (Details) - USD ($)	6 Months Ended
Mar. 31, 2025	Mar. 31, 2024
TAXES
Loss before income taxes	$ (5,054,300)	$ (2,244,424)
PRC
TAXES
Loss before income taxes	(971,211)	(432,079)
Hong Kong and other jurisdictions
TAXES
Loss before income taxes	$ (4,083,089)	$ (1,812,345)

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

No definition available.

Name:	ntcl_IncomeLossFromContinuingOperationsBeforeIncomeTaxesNoncontrollingInterestsTotal
Namespace Prefix:	ntcl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration