The phrase "advised to sit" is correct and usable in written English.
It can be used in contexts where someone is being recommended or instructed to take a seat, often for reasons of comfort or necessity.
Example: "After the long journey, she was advised to sit and rest for a while."
Alternatives: "recommended to sit" or "instructed to sit".
Marina suddenly grasps why people faced with sudden shock are often advised to sit down.
When people first start taking nitroglycerin, they are usually advised to sit down to avoid falling.
Business owners contemplating a float would well advised to sit on their hands if they can afford to.
The new screen is so large (7.5 feet across) that owners are advised to sit at least 11.5 feet away to fully appreciate the picture.
During the intermission the player reported dizziness and was advised to sit out, but the coach suggested he play the second period and "skate it off".
However, with on-going global economic concerns and upcoming data from the euro zone investors may be well advised to sit on the sidelines.
In fact, for real progress to be made in resolving the longest-standing adversarial relationship the United States has with any country in the world, journalists would be well-advised to sit on their hands and keep their mouths shut.
"A day or so after the event, we advised people to sit still," said Edward M. Kerschner, chief global strategist for UBS Warburg.
An hour after the concert started, people still were flowing into the park and police officers advised them to sit on the side of the roadways because the Great Lawn had passed even its standing room capacity.
He advised customers to "sit tight" and assured them that engineers were working as fast as possible.
A nurse treated him for a low level of oxygen in his blood, and advised him to sit up if he had trouble breathing.
