What benefits should be provided by employer while relocating office within the country

I would like to know what the benefits should be provided by the employer while relocating their office within the same country. Can employees refuse to relocate?
Should the employer revise salaries where the cost of living is higher in compare to present location?
Please tell me the conditions and detailed information on this.

While joining, your employees must have signed certain terms and conditions of the job. If transfer was a condition, then employee cannot refuse the same.
Normally, companies give relocation expenses to their employees when they are transferred for company business.
Allowances could range from transportation charges for vehicle, luggage, personal effects to airfare/ AC travel etc. depending on status and appointment held.
Allowances like HRA, CCA would be given as per company policy.