Nibir bone j opening riff and chords

I have tried to figure out the beginning riff of the song "Nibir bone j.." by Jayanta hazarika.


The riff is in harmonic minor scale

G minor strum (preferably in the 10th fret) and then, (alphabet= string, num= fret position)
11B+10e 10e 13e 11e 10e 13B 12B 10B
10B+10e 10B 13B 11B 10B 12G 11G 13D
13D 11G 12G 10B 11B 10B
12G 10B 12G 11G 13D 12D 10D 13A 12A 10A
...

Then the song follows a chord progression of G minor and F major.