What suffix should be add in the word industry?

It depends on what you want to convey! Here are some options and what they mean:

-al: Creates an adjective: industrial (relating to industry)

-ize: Creates a verb: industrialize (to develop industries)

-ization: Creates a noun: industrialization (the process of developing industries)

-ist: Creates a noun: industrialist (a person who owns or manages an industry)

Let me know what you want to express, and I can suggest the best suffix for you!