Have a look here :

https://search.earthdata.nasa.gov/search

Under 'instruments' select ASTER, then use the map tools to reduce search to your area of interest.

Dear Akash

You may explore the scene by creating an account at

https://earthexplorer.usgs.gov/

Moreover, you may browse the following links

http://reverb.echo.nasa.gov/

http://www.landcover.org/data/

https://www.researchgate.net/search.Search.html?query=free%20satellite%20&type=question

https://sentinel.esa.int/web/sentinel/home

Thank you Jahangir sir and Colin Sir for responding.

try this: https://glovis.usgs.gov/

you can at

glovis.usgs.gov

earthexplorer.usgs.gov

earthexplorer.usgs.gov

have a look here as well, several other pages are introduced to download your ASTER data

https://terra.nasa.gov/data/aster-data

The LP DAAC ASTER Level 1T (AST_L1T) terrain-corrected image product is available for immediate download to all users at no charge. You can use any of the following methods to download the ASTER Level 1T (AST_L1T) data:

• NASA Earthdata Search – enter ASTER in the Earthdata search and select ASTER Level 1 precision terrain corrected registered at-sensor radiance V003 data set to begin your search.
• LP DAAC Data Pool – direct access to data directories for immediate HTTP retrieval is available via the ASTER collection.
• USGS GloVis – under Collections, select ASTER, choose L1T Day (VNIR/SWIR/TIR) or L1T Night (SWIR/TIR) collection to find AST_L1T data at no cost.
• USGS Earth Explorer – under Data Sets, select NASA LP DAAC Collections, ASTER Collections, ASTER Level 1 precision terrain corrected registered at-sensor radiance V003 data set to begin your search.