Hi , Company can reduce basic salary after 2...

The company does not have the right to reduce the employee's salary except with the agreement and consent of the worker to that, and to grant him a salary less than the salary recorded in the contract. The worker can file a complaint with the Ministry of Human Resources and Emiratisation against an owner in order to obtain his salary recorded in the full labor contract.
You can also ask to terminate the employment contract because the employer violated the profession registered in the employment contract, in addition to granting you a lower salary.
Also, that case may take between three to six months, on average, because if the Ministry of Human Resources fails to solve this problem, it will send it to the labor court in order to issue a binding court against ruling the employer by paying the employee's salary as recorded in a contract the work.
Here is the text of the UAE Labor Law, and related to your inquiry
Article (58)
It is not permissible to prove the fulfillment of workers with the wages due to them, whatever their value or nature, except in writing, acknowledgment, or oath.
Any agreement to the contrary is considered void, even if it was prior to the implementation of this law.
Article (121)
The worker may leave work without warning in one of the following cases:
- If the employer violates his obligations before the worker in the articles stipulated in the contract or the law.
- If the employer or his representative legally assaults the worker.