en.wikipedia.org/wiki/Demographics_of_Nepal

The total in the table does not match the numbers listed immediately above it.

Using the figures shown in the article:

• India 2,926
• UAE 400
• Saudi Arabia 297
• Australia 219
• United States 205
• Qatar 200
• Japan 156
• United Kingdom 62
• Iraq 30
• South Korea 22
• Hong Kong 16
• Canada 14
• Malaysia 6
• Singapore 4
• China 3.5

These sum to 4,560.5 thousand, i.e. about 4.56 million. That is almost double the stated "Approx. total" of 2,355 thousand.

So the total shown in the table is mathematically inconsistent with the article’s own row values.

This sentence misdates Nepal’s national population census.

Nepal’s National Statistics Office lists "National Population Census 2001, Tenth Census" as the census for that period. The same catalog also lists the later 2011 and 2021 population censuses, showing the regular census sequence. The 2000 item in the NSO catalog is a different dataset ("Between Census Household Information Monitoring and Evaluation System 2000"), not the national population census.

So calling it the "2000 census" is incorrect; the relevant official population census was the 2001 Nepal census.

The claim gets the date wrong.

An official UN-hosted copy of the parliamentary act is titled "Proclamation of the House of Representatives, 2006 (18 May, 2006)". Contemporary reporting on that same action also states that on 18 May 2006 Nepal’s parliament voted to make the country a secular state.

So the declaration of Nepal as a secular state occurred on 18 May 2006, not 19 May 2006.

This sentence combines multiple factual errors.

1. Nepal’s new constitution was not promulgated in 2008. Nepal’s Ministry of Foreign Affairs states that the Constitution of Nepal was declared by the President on 20 September 2015 after adoption by the Constituent Assembly.

2. The major citizenship-document distribution drive happened under the 2006 Citizenship Act and in 2007, not after a 2008 constitution. UNHCR reported that Nepal conducted an extraordinary citizenship operation in which some 2.6 million people received citizenship certificates, and a UNHCR report further notes that a government task force distributed 2.6 million certificates in 2007.

3. Those recipients were not described by these sources as “4 million Indian immigrants.” The 2.6 million figure refers to people in Nepal receiving citizenship certificates; the article’s phrasing about "4 million Indian immigrants" does not match the authoritative descriptions above.

So the statement is incorrect in date, legal context, and the number/nature of the people involved.