Appointment letter legality - "if the performance is found to be unsatisfactory; then services could be terminated, without notice and without assigning any reasons"

Can I add the point on Appointment letter "if the performance is found to be unsatisfactory; then services could be terminated, without notice and without assigning any reasons". It is legal or illegal kindly give me some suggestion.

Dear All
Can I add the point on Appointment letter ( if the performance is found to be unsatisfactory; then services could be terminated, without notice and without assigning any reasons.
It is legal or illegal kindly give me some suggestion
Best Regards,
Nilanchala Das
HR Manager-Vatsalya Empire Ventures Pvt Ltd.

Dear Nilanchala Das,
Nothing wrong to terminate services if the performance is unsatisfactory. However, under the provisions of Article o25 of the constitution, following the principles of natural justice is mandatory. To follow the principles of natural justice, it is important to conduct domestic enquiry.
Therefore, you cannot include a statement in the appointment letter like "if the performance is found to be unsatisfactory; then services could be terminated, without notice and without assigning any reasons." It is illegal to do so.
Thanks,
Dinesh Divekar