MS SQL to Postgres

I am in search of the best practices to migrate from an MS SQL database server to PostgreSQL 16

Existing DB server MSSQL with 6 Million records and 3.5 TB  with 424 Tables running from 2019 onwards.

Each table has 5 to 16 columns ( basically text, numbers, lat long coordinates , time stamps, and images/voice file (stored in archive folders)reference links, etc.  ).

I am in need to port / migrate all this data from this MS SQL server to Postgres16 .

1. What are the best methods and practices folks employ to do this kind of data porting operations?  

2. what are the tools and techniques to explored / employed for this

3. How much time is consumed by employing the right tools, the entire porting of 6 million records of 3.5 TB size to Postgres 16 takes 

4. Any hurdles or challenges or risks 

Kindly enlighten me with the best practices and  reference materials / links or tutorials to perform these operations successfully.  

Thank you, 

Krishane