validation rules is applicable to all page layout of a standard object but i want it has to apply for a particular page layout not other page Layout. Could any one help me?
Actually Validation rules are record specific and not page layout specific
If you have validation for e.g. a field has to be required when a record is entered - this is something that can be managed using the required validation controlled by page layout but for other validation rules you will have to probably create a visualforce(VF) page rather than a pagelayout and then apply custom validations on the VF page as shown in the following example: http://salesforcesource.blogspot.in/2008/09/how-do-custom-validations-in-visual.html
Actually Validation rules are record specific and not page layout specific
If you have validation for e.g. a field has to be required when a record is entered - this is something that can be managed using the required validation controlled by page layout but for other validation rules you will have to probably create a visualforce(VF) page rather than a pagelayout and then apply custom validations on the VF page as shown in the following example:
http://salesforcesource.blogspot.in/2008/09/how-do-custom-validations-in-visual.html