i would like to setup email alert which should run on Mon , Tue , wed , thur, and Friday
everyweek @ 04:00 AM IST
A web resource a lot of people use, is https://crontab.guru/. I'm not affiliated in any way with the tool, but for years, it's not steered anyone wrong. What's cool about it is it can help you understand the plain-English of the cron expression @ITWhisperer gave you.
Check here to see the expression pre-populated: https://crontab.guru/#0_18_*_*_1-5