How to put the below data in 3NF? I need to put the data from the diagram in 3NF (third normal form)
Assuming that your table is for storing Sales Record, we can do the following:

For 1st Normal Form:


Eliminate columns with duplicate (not really eliminate but rather re-arrange).

I just separated the columns with repeating data and made them new rows.


For 2nd Normal Form


The table should be in 1NF
Remove subsets of data that apply to multiple rows of a table and place them in separate tables.
Create relationships between these new tables and their predecessors through the use of foreign keys.

Created new table for the Seller, Customer, Product, Rating and the Records.
Seller No., Cust ID, Prod ID and Prod Rating are their primary keys (which is foreign keys for Sales Record Table)


For 3rd Normal Form


The table should be in 2NF
Remove columns that are not dependent upon the primary key.

I usually encounter this form when dealing with addresses. As you can see i added the table City and used Zip Code as a foreign key.
I also added a primary key in Sales Record table (Record ID).


You can read about normalization here and here.

Last word:
Normalization is good for reducing data redundancy and ensuring that their relationships is used. Useful with JOINs but can be a headache when there is too much data and tables.