How to find proper joins for jai_tax_lines to get correct tax details

Dear All,

We are upgrading from R12.0.6 to R12.2.6 including with GST.

Now, my requirement:

1) What are the tables to be used to get the Tax details(In modules like Purchasing,Order Management,Paybles,Receivables,Receipt,Shipping(P2P,O2C..)...)

2) Proper join conditions for the table "jai_tax_lines".

3) For any table (ex: ap_suppliers) ,how to know what are the columns list with data type and what are the proper joins for that table.(may be from metalink we can get this,i forgot navigation)

Thanks in advance..

Regards,

Srikanth.