Bonus Calculation - employer is restricted to pay bonus for above mention limit?

My queries
Regarding Bonus Disbursement.
1.) Bonus to be paid on 7000 or Minimum wage (whichever higher) up to 21000.
Does it mean that employer is restricted to pay bonus for above mention limit?
Does employer is bound to pay bonus to employee holding basic 21001?
Regarding Calculation:-
E.g
2.) XX company holds 100 employees and the bonus amount to be distribute is rs 100000 after allocation and surplus.
Now bonus is to be distributed.
a) How percentage is derived ? b) Or i should divide 100000/100 employees and distribute ?
Please clear with law reference if possible attach the calculation sheet and necessitate forms.
Thanks in advance.

Dear Himanshu,
As a answer to your first point ; No employer is not bound to pay the bonus to the employees with salary more than 21000/-. But employers prefer to pay the bonus as ex-Gratia to them with salary more than 21000/-.
With reference to your second and third point, i want to ask you a counter question that if bonus is the percentage of the basic salary (i.e. 8.33 to 20 %) how can you distribute it equally. Do all the employees have same salary? If they don't everyone is entitled to bonus as per their basic.
Now;
Annual Bonus = Annual Basic + DA salary * 8.33 to 20 %
It depends on the predetermined percentage of bonus your company offer.

Thanks Aniket for sharing knowledge,
However still i have doubt that , how percentage is decided and with what method.
Say for e.g Company is in profit of 90 lac after set off & set on of allocable surplus.
Now how that percentage from 8.33 to 20 is decided for 90 lac or explain me how that 90 lac will be disbursed to applicable staff.
Thanks in advance

Dear Himanshu,
You tell me how the bonus was disbursed last year (i.e. what percentage). Its the decision of management how much they want to disburse (8.33 % to 20 %). Lower and higher limit is mentioned in payment of bonus act. Please go through it for clarification.

Dear,
Details will be elaborate so that clarify your doubt
Regards
Mohana