MSFS default airports for Bangladesh are usable, although gate numbers and taxiway labels are wrong because they are AI generated. However, airports in Bangladesh have relatively simple layout and it is easy to navigate using the Bangladesh AIP which is publicly available: http://www.caab.gov.bd/aip/aerodromes/adall.pdf
Parking stands may not always match, particularly in case of Dhaka. You may use the following sceneries (freeware):
Pay-ware Dhaka (VGHS) scenery is available on Simmarket:
Highly detailed Scenery for Dhaka developed by Bangladeshi developers: https://secure.simmarket.com/final-approach-design-simulation-deshi-sceneries-hazrat-shahjalal-international-airport-dhaka-vghs-dac-p3d4-5.phtml
Dhaka Airport scenery developed by MFSG is also available:
The default FSX and P3D scenery are usable. There are a number of freeware scenery available on various flight simulation websites as well.