HCL Technologies — Offer letter not initiated

Have got confirmation that i am selected for the software engineer post on 18/3/22 and will recive my offer within 2-3 weeks maxm,
Now its almost more then 3 months aaof today 23/6/22
My offer letter is not given to me
HR always replies with 'please have a patience'
how much patience should i have to show?
When will all these process will be complete
I havn't applied any other company due to this job.. Please give some confirmation!!
Is that for hcl works 'customer 2nd employe 1st'
I dont think so
Please do something