Give some unique tag to textfield and button by below way:
/////////////////////////////////////////// ////////This is the important part///////// ///////////////////////////////////////////
UITextField *field = [[UITextField alloc] initWithFrame:CGRectMake(14, 6, 245, 31)];
self.sendButton = [[UIButton alloc] initWithFrame:CGRectMake(265, 1, 50, 40)];
[self.sendButton setTitle:@"Reply" forState:UIControlStateNormal];
[self.sendButton setTitleColor:UIColorFromRGB(0x960f00) forState:UIControlStateNormal];
self.sendButton.tag = indexPath.section *1000 + indexPath.row;
[cell addSubview:self.sendButton];
[self.sendButton addTarget:self action:@selector(sendReply:) forControlEvents:UIControlEventTouchUpInside];
field.tag = self.sendButton.tag + 1;
[cell addSubview:field];
cell.accessoryView = nil;
Now on button event,
-(void) sendReply:(UIButton *)sender
{
UITextField *field = [YOOUR_TABLE_VIEW viewWithTag:sender.tag + 1];
//Do you coding here
}