Dont know about tranny mechanic in pindi, sorry.
But I had similar sort of issue with my car gear box, the estimated repair cost was gonna be around 5K including bearings, synchronizer, shifter fingers and a 5th gear.
So I went to Bilal Gunj and replaced the old gear box with a kabli. Cost was 6K including the old tranny adjustment of 2K (8-2=6).
It is doing well for a year now with me.
If you opt this dont forget to replace all the rubber seals and the sealant between the two halves of the box and also the fifth gear black tapaa.
There is 99% chance that they are gonna leak the moment you put the gear oil in. So keep it in mind.
And please dont forget to share the workshop manual download link.