I just picked up a CD called "Shankar Ghosh Tabla Nusrak Tal and Tintal" It is very interesting , there is no accompaniment just Shankar Ghosh on tabla. There is a lot of information in the fold out and it sez this about Peshkar "Most musicians would recognise the opening composition as a peshkar (introduction), but Shankar Ghosh has explained that in the Farukkhabad tradition musicians use the word Suruwat (or shwu'aat) instead which means beginning."
Since Nasruk tal is 9 matras this might be why Rishi said it was a tisra peshkar. But the vibhag breakdown is 2+2+2+3 (Zakir uses this often on Shakti albums) .
Anyway the Surawat peshkar theme is written in the notes and explains that the first section is called Khuli (open) and that the second section is called Mudi (closed) Khuli |dhi-kre, dhin dha,| trekre dhage, dhin na, | dhin na, dha tet,|dha-trekre, dha-dhage, tun na| Mudi Tin-kre, tin na,| trekre taka, tin na, | dhin na, dha tet, | dha-trekre, dha-dhage, dhin na|
So there you go new info about the peshkar. Well I guess you will probably want to know the theka for Nasruk. |dhi, na,|dhina, kat,|dhi-kre, dhina,|dhage, dhina, kata| The claps are written as +,0,2,3 so the second vibhag is khali