migrating exchange to office365- hybrid mode

It depends on how many users you need to migrate and the timeframe. Review concepts and limits here:

https://docs.microsoft.com/en-us/exchange/mailbox-migration/mailbox-migration
Vutover migration means you need not install aadconnect and that you will be able to end the migration in a weekend. This is suitable for let's say hundreds of users (depends on the mailbox size)
At the other end we have hybrid migration which is suitable for larger exchange installations and user base. You need to install aadconnect, plan and set up a mail flow, migrate users in batches , and keep aadconnect and exchange on prem probably, even though you may be able to dismiss them at a certain point, and manage your mailboxes otherwise (requires good expertise on AD and exchange).


Staged migration is also on option.


Try to imagine a migration path and come back with your doubts.

According to your user base, You can decide Exchange migration. I would advise you to start with Exchange Deployment Assistant tool. That will give you brief idea. Below is the link:
https://docs.microsoft.com/en-us/exchange/exchange-deployment-assistant?view=exchserver-2019

The deployment assistant is a valid tool which recently has been changed to require a tenant and a subscription, unfortunately. You can neverthless setup a test account to use it. IMHO some reading is required beforehand to have a meaningful test environment.