Once convicted and accused send to prison then it is very difficult to get bail of accused. After sentencing, if accused had made appeal then, at that time accused should file Appeal as well as shouls seek bail till disposal of appeal. If he is already put behind bar then there are rare chances of getting bail.
Lalu, Salman Khan they got bail after conviction. But Talwars are not on bail. So bail after conviction is for rich and mighty guys. Still if you have filed the appeal against conviction order, you may seek bail.