Plesae could you advise me whether in Turkish Law a purchaser of a property who has signed a written contract can unilaterally cancel the contract

Further if the purchaser refuses to complete the purchase and pay the balance of monies owed is this a repudiatory breach which would allow the seller to terminate the comtract and claim damages?

or does the seller have to serve a notice on the purchaser requiring completion by a given date before the contract can be terminated?

The contract is silent on these issues.

Thankyou