If I buy or sell shares on Ex-Date of Dividend announcement, Do I receive the dividend? What is the record date?

You are not eligible to receive dividends if you buy shares on ex-date, you will be eligible only if you buy before ex-date.

Buyer of the shares is not eligible to receive dividends if bought on ex-date, while seller of the shares on ex-date will be eligible to receive dividends.

So the dividends received will be passed on to the seller of the shares.