Who can be FCA

One who completed CA and who will be practice more than 5 years will be awarded FCA....

The one who passes CA final both groups and gets registered himself/herself with the ICAI becomes ACA from the date of registration as a member.

An ACA becomes FCA on completing 5 years of practice but only if he/she applies for FCA.  It is implied here that an ACA  can practice only after obtaining COP (Certificate of Practice) from the I.C.AI.

Is there any separete certificate required for Practicing after passing CA...

I.e. what if we are looking for employment in any company?

Yes you need to apply for COP- CERTIFICATE OF PRACTICE if your willing to do practice. If your looking for employment than no need to apply for COP just you can go ahead with CA completion certificate..

Best of luck