There are few things to consider here:-

First, NO we cannot guarantee your rankings because:

1) We don't own the search engines.

2) SEO techniques that used to work last month may not apply today because of changes to the search engines' ranking methods.

3) Without proper budget no way we can push your site ranking.

4) Without your serious commitment we can't do anything about it.

Second, YES we can guarantee your rankings only if:

1) You willing to pay for it.

2) You dare to take the challenge and have no budget limitation. It can be done with implementation of all web marketing techniques we know. We dare to say it will boost your site to first page.