Fixed Gross Pay ( Included all the fixed allowance such as basic, HRA, Conveyance Allowance, Medical allowance etc)
Benefits (Company contributions such as ER contribution of ESI & EPF, gratuity, Bonus, Insurance etc...
Variable pay (Such as performance bonus/incentives)
If performance pay is fixed every month (but you pay quarterly) then you can include it in CTC. If it's fixed then basic pay can be set accordingly and if it's not fixed (changes every quarter) then you need to set basic excluding performance pay.