The concerns raised by Congress regarding a Chinese national allegedly duping people in Gujarat can be summarized as follows:

• Congress is demanding a white paper from the government to provide a detailed account of the incident. This indicates their concern over the lack of transparency and clarity surrounding the case.
• The alleged duping of 1,200 people by a Chinese national raises questions about the effectiveness of the government's security measures and border control, as well as their ability to handle such fraudulent activities.
• Congress believes that this incident highlights the potential risks and vulnerabilities associated with foreign individuals or entities engaging in fraudulent practices within India. They are concerned about the potential impact on the country's economy and the security of its citizens.
• Furthermore, Congress demands that the government take appropriate legal action against the alleged offender and ensure that the victims receive justice and compensation for their losses.
• The party is also keen on understanding the steps taken by the government to prevent similar incidents in the future and protect the interests of the people of Gujarat and the nation as a whole.

Overall, Congress is raising concerns about the government's response, the security lapses, and the need for transparent and decisive action to address the alleged duping by a Chinese national in Gujarat.