I purchase an apartment for $ 1.7m and paid first instalmment of 250k ,Before the second installment I sell the apartment at the value of 1.9m .Please tell me how to record the journal entry .

Here is the simple version of the transaction, not considering any tax, transaction cost or depreciation:

Bought-Dr. House 1.7M Cr. Payable 1.7M
Installment-Dr. Payable .25M Cr. Cash .25M
Sold-Dr. Cash 1.9M Cr. House 1.7M
Payoff the loan-Dr. Payable 1.45M Cr. Cash 1.45M

Sale and purchase account

Sale and purchase accounts entres

sale and purchase accounts entree

How prepare cash book and ledger with vouchers

*Do not tag onto other people's threads. It just keeps old threads alive and drags irrelevant stuff out. (Yours is not even related to this one.)
*Don't double post. It's unnecessary and will not get you help any faster.
*The entries for purchases and sales is an entire chapter. We can't lecture entire chapters on a forum. Narrow down a question to one thing that someone can actually answer.

Consider this thread gone, start you own thread, and ask a more specific question.