Update free-courses-hi.md (#8483)

Added a video course on Discrete Mathematics

courses/free-courses-hi.md

@@ -350,6 +350,7 @@
 
 * [Discrete Mathematics](https://www.youtube.com/playlist?list=PLxCzCOWd7aiH2wwES9vPWsEL6ipTaUSl3) - Gate Smashers, `tch.:` Varun Singla, `tch.:` Naina Wadhwa Singla
 * [Discrete Mathematics (Full Course) By Dr.Gajendra Purohit](https://www.youtube.com/playlist?list=PLU6SqdYcYsfJ27O0dvuMwafS3X8CecqUg) - Gajendra Purohit
+* [Discrete Mathematics Tutorials In Hindi | B.TECH- B.E.-UGC NET- GATE- LECTURES In Hindi](https://www.youtube.com/playlist?list=PLL8qj6F8dGlTX359q-PBBUFw3BrBvAxq3) - Deepak Garg
 * [Statistics And Probability](https://www.youtube.com/playlist?list=PLU6SqdYcYsfLRq3tu-g_hvkHDcorrtcBK) - Gajendra Purohit