Why cant i render selection to sample with tracks that have send device?
It depends, do you “Mute source” ?
yes, i mute source…
and if i dont then it renders only raw signal without effects that i put on send channel. is it supposed to be that way?
Mark the area to render in the send channel, then it works.
hey i never knew 
thanks for the tip!! i didnt know that 
but still it isnt exactly what i wanted because now it renders only wet signal. What i wanted is that suppose i make a loop, bassdrum on one track, snare on the other, hihat, perc etc etc… now suppose i want to apply some effects on only bassdeum and snare so i put a send device on those two tracks and apply effects on send channel. Now i want to decrease the effect that it has on snare, i press the keep source button on snare track send device and dcrease the “amount” a little bit. Now it sounds the way i want and i decide to render the whole loop (traks with send device, traks without it and traks with “keep source” option) to sample…
EDIT: if i could select the tracks + send track then it would render OK i guess, but i cant select that way… or can i? 
The tracks you select will render with the effects that are being applied to those tracks since the output signal is just being diverted to the sampler.
The whole behaviour is just as logical as when making Renoise play the song realtime, if you would mute the send-track, you won’t hear the original track playing either if the source was muted, so why would you expect the “render to sample” option, to behave any different?
The routine goes:Which notes are selected? Create streams from area ,which tracks are selected?->stream outputs from tracks and applied effects to sampler.
If you want a particular order of tracks and sendtracks to be rendered, just drag all related tracks next to eachother and next to the master-track, then drag the required sendtracks next to the master-track.
Take care the master-track volume is at least set to -5db (as you can’t drag the sendtracks to the left side of the master-track and muting the master-track gives you a silent result), then render your selection.
yeah thanks for the answer vvoois, the dragging tracks next to master and send track is a workaround but its kida cumbersome, and i didnt quite understand why is it logical not to render send track? Send track isnt exactly a track, its just a device that i can route signals thru, and if i select a track that has send device then IMO its logical that i want the signal to be rendered thru send track, otherwise i wouldnt put a send device to that track in the first place or just unticked send device so the signal wount be routed… 
In this case i would simply mute all the channels you don’t want to be included while rendering, disable the effects on your master channel, press STRG+A and render that to a sample. Still lot’s of clicking, but it works. Another method, add an additional send channel and route all the stuff you want to render to this channel and render it, you could group your channels like drums, leads and so on.
It would be nice, if one could do multiple selections with add, subtract like masks in graphic programs.
I did not said it is not logical to render a send-track, “If you would mute…” was meant as an example to show what Renoise does realtime, when rendering to sample, this is not going any different.
If you want the raw sample, then indeed untick the send-device or just press the “Keep source” button on the send device.