Which of these two is right?
This project can raise the sale at the global level
This project can raise the sale in the global level
Neither is correct. I suspect what you mean to say is
This project may increase global sales.
If you want to stay as close as possible to the original, then say
This project can raise sales at the global level.
The latter will be understood and sound idiomatic even if a bit verbose.
The usual preposition to use with "level" is "at". Something is at a particular level. I would use the plural of "sale" too, and omit the definite article, since "sales" is general.
This project can raise sales at the global level.
The preposition "in" can be used with a different noun, say "market". In this case
This project can raise sales in the global market.