Regarding Non Decided Land

Which Assessment year?

FY 2018-19, but land purchase in 2008, 2009, some father's land transfer in 2013

You mean to say in the Balance sheet. Right !
If lands are in individual name as an investment and not a part of business assets (if any) then you may not include in Balance Sheet of ITR3.

But if you included in last year, you have to continue .

For inclusion of omitted land , you can simply file revised return under 139(5) upto 31-3-2020.