Form 3CEB is basically filled by the company with form 3CD under sec 92A TO 92F of income tax act.These section basically relating to TRANSFER PRICING,
Form 3CEB is manadatory to filled if the company engaged in any of the international trasation with any associate enterprise.
In that form basically u need to give a detail of ALL the internation transaction with associate enterprises.
If you want to know about it more then let me know i will provide you the details of the relevant sections of TRANSFER PRICING.