what should the SM and the PO do when the stakeholder unhappy

could the stakeholder see the increment before the sprint review ?

There's nothing preventing this. It depends on the relationship between the organization and team building the product and the stakeholder. The role of the Product Owner includes representing all stakeholders to the team and the Product Owner should be working with the rest of the team every day and in regular contact with all of the stakeholders. However, getting feedback directly from stakeholders is best, so maximizing that feedback is probably in the best interests of everyone involved.

Who determines the quality of the product the stakeholder or the scrum team ?and if the stakeholder is not happy when they see the quality what should they do ?

The Developers are responsible for building quality into the product, but the stakeholders (through the Product Owner) are responsible for setting what is expected in terms of product and process quality. If the stakeholders do not believe that an Increment has sufficient quality for potential use, then the Scrum Team should enhance their Definition of Done to ensure that all of the work meets the quality expectations and consider any remediations necessary to bring the existing product up to this level of quality as a form of technical debt.

The Scrum Team may enforce higher levels of quality than the stakeholders demand, but cannot produce Increments that are not sufficient for use.

what should the SM and the PO do when the stakeholder unhappy when they sow the Increment in the sprint review ?

This is a good opportunity for a discussion. Understand why the stakeholder is unhappy and figure out what the team can do to make them happy. The Product Backlog can be adjusted to work toward an Increment that meets the stakeholders' expectations.

1-what should the SM and the PO do when the stakeholder unhappy when they sow the Increment in the sprint review ?

Use the Sprint Review for its intended purpose - a collaborative working session in which the outstanding requirements are better understood. It's an opportunity to get the Product Backlog in the best possible shape for the next Sprint, which will very shortly begin. 

2-could the stakeholder see the increment before the sprint review ?

Would the Developers find this helpful?

3-Who determines the quality of the product the stakeholder or the scrum team ?

The Developers who are doing the work. No-one else is in a position to do anything about it and build the necessary quality in.

and if the stakeholder is not happy when they see the quality what should they do ?

Flag the issue with the Scrum Team as quickly as possible, because Scrum is not being implemented well. Everyone on the team has a relevant accountability to fulfill and will have actions that ought to be taken.