Can I leave company within 3 days from date of joining because of their poor hr policies

Hi , I joined compaNy today at noida on 18th Jan 2021. I found they have three Month notice period for employee and one month notice period for employee during probation. I asked them to correct but they are discussing as their internal rules secondly they have given me designation of sr manager hrbp and their welcome mail says that I am designated as Head HR as per me both designation has different responsiblities and compensation. I asked them on very same day of joiNkng in writing to correct my appointment letter with head hr along with new compensation. They are saying it's internal thing but they are expecting same output of head hr, which is not justifying. Secondly they have different different Notice period and clause of every empLoyee. I do not wish to continue here. If I leave this company, do I need to serve notice period or need to pay notice pay salary as per them. Because their one clause in bn probation period says I have to serve notiCe period of 3 months but does not say anything about notice pay amount and other clause in termination says you have to pay one month notice period salary if notice is not served. There is ambiguity in their appointment letter. Please suggest.