RMAN restore

I check my backup full and RMAN shows me that is correct

RMAN-08502: set_count=26 set_stamp=495201800 creation_time=28-MAY-03
RMAN-08023: channel t1: restored backup piece 1
RMAN-08511: piece handle=Backup_full_DATABASE_26_1 tag=null params=NULL
RMAN-08098: channel t1: validation complete


But when I try to restore controlfile or database It says
the backup is not valid

RMAN-03002: failure during compilation of command
RMAN-03013: command type: restore
RMAN-03002: failure during compilation of command
RMAN-03013: command type: IRESTORE
RMAN-06026: some targets not found - aborting restore
RMAN-06024: no backup or copy of the controlfile found to restore

How to specified during restore the name
of piece handle = 'Backup_full_DATABASE_26_1'
something like that
run {
allocate channel t1 type 'SBT_TAPE'
parms 'ENV=(NSR_SERVER=toto.com,NSR_DATA_VOLUME_POOL=Default)';
restore controlfile;
release channel t1;
}

Post output of following:

>rman

list backup of controlfile;

RMAN> list backup of controlfile;

List of Backup Sets
Key Recid Stamp LV Set Stamp Set Count Completion Time
------- ---------- ---------- -- ---------- ---------- ----------------------
1610 21 495202466 0 495201800 26 28-MAY-03

List of Backup Pieces
Key Pc# Cp# Status Completion Time Piece Name
------- --- --- ----------- ---------------------- ------------------------
1611 1 1 AVAILABLE 28-MAY-03 Backup_full_DATABASE_26_1

Controlfile Included
Ckp SCN Ckp time
---------- ---------------
3231838458144 28-MAY-03

Confirm that prior to restore:

Instance is started , but database is not mounted.
You connect to the catalog database and target instance.
You backup set is accessible for the restore job.

Where is you backup stored?

My database is nomount and i want to restore controlfile
my backup is store in a tape.
When I connect to RMAN and my terget database I run this :

run {
allocate channel t1 type 'sbt_tape'
parms 'ENV=(NSR_SERVER=toto.com,NSR_DATA_VOLUME_POOL=Default)';
restore controlfile;
release channel t1;
}

I know it sounds simplistic, but is there any way to make sure that "the tape" has "the file"?