Dear Ahmed El-Zeiny

Via ENVI 5.3 you can’t read and calibrate(Atmospheric correction) Sentinel2 images.

At this time you should calibrate sentinel2 L1C(TOA reflectance) to surface reflectance(BOA) via Sen2Cor tool.

You can download Sen2cor tool via following link:

http://step.esa.int/main/third-party-plugins-2/sen2cor/

for reading Sentinel2 product via ENVI5.3

1-read it via SNAP

2-open one Band in SNAP

3-save product

4-open ENVI5.3 and read all bands from saved product folder individually

5-do layer stacking in ENVI(change Datum to desired datum for example WGS84)

The fastest way is to do it by using the sen2cor L2A_Process tool developed for cmd.exe

You just need to write your code

C:\Sen2Cor-2.4.0-win64>L2A_Process.bat sentinelimagen.SAFE

That's all, no need softwares

I hope this will help you

sen2cor L2A https://www.youtube.com/watch?v=VNG1KRcUzao&t=2s

You can process Sentinel images by using SNAP software

If you have funds, go for ENVI 5.5 along with FLAASH module to correct Sentinel-2 data.

You can also use Qgis's Semiautomatic Classification plug-in to perform atmospheric correction of Sentinel-1 imagery.

Yes you can use QGIS's SCP for Snetinel-1, Sentinel-2,Sentinel-3 Aster, Lansat,MODIS,GOES to do DOS (Dark Object Subtraction)