i have been working in another company for six...

We would like to inform you that according to the Qatari Labor Law, if you have work with another company than the one which sponsored you and the company doesn't know, then yes you will face legal action and may deprive you from your labor rights.
However, if the company already knows that, and you don't have agreement, then you can prove that according to the law and you will not face legal issue.
You can ask for your labor rights by the court if there is a case.
If you have another question, feel free to ask and we will answer with pleasure.