Please Clarify your statement "there is option of extending for a year"
By virtue of your Designation, you do not come under the purview of Industrial Employment Standing Orders Act & relevant Rules
Retirement after attaining 58 years in your case,appears to be fair
What is your company profile?
If it is a Factory or establishment, the retirement rules apply as per Standing orders or Factories rules / shops and establishment rules.
If the company does not want to extend your services you cannot fight back on that reason.