Tamil Pronouns in the Noun Cases

Tamil nouns take on noun case endings instead of having prepositions like we do in English. Some of the noun cases are different for the pronouns than for regular nouns.  In this spreadsheet, I have posted a chart based on Balasubramaniam's Tamil: A Foundation Course (1995, p88). There are two columns for the genitive case, just as there are in the original. I am not sure what the reason for that is, but am trying to present the information in tact.

Keep in mind that these are pure Tamil forms and are not always used in spoken Tamil. When I have more complete information on the spoken forms, I will create another spreadsheet for comparison.

Pronouns and possessive forms

How to make possessive forms of pronouns and regular nouns:

Pronouns we memorize, though you do see some patterns throughout:

• I = நான்; my=என்
• you = நீ ; your = உன்
• you (polite or plural) = நீங்கள், your= உங்கள்
• we (exclusive)= நாங்கள், our=எங்கள்
• we (inclusive)= நாம், our= நம்
• he/his அவன்/இவன்;  theirs = அவர்கள்/இவர்கள்
• she/her அவள்/இவள்;  theirs = அவர்கள்/இவர்கள்
• he/she/his/her அவர்/இவர்;  theirs = அவர்கள்/இவர்கள்
• it (close, here)= இது; its=இதன்; theirs (neuter)=இவைகளுடைய
• it (far, over there)=அது; its=அதன்; theirs (neuter)= அவைகளுடைய

Regular and proper nouns seem to have two options:
Add the suffix "oodaya" or "in"
above we see that "it" uses "ளுடைய"
other examples: house= வீடு; house's = வீடின்
I am currently in the polling stage to find what the rules are.
When do you use "in" and when "oodaya"???
Are they essentially synonymous?

Possessive/Genitive form is expected in chapter 5 of Hart's Tamil for Beginner's though it is introduced without much explanation, and the accompanying grammar book does not have a section for it...
In Asher's Colloquial Tamil "ooda" is used to designate the possessive form: "peeraasiriyar professor; peeraasiriyaroo∂a professor’s."