startup pfile=inittestrac.ora ORA-29760: instance_number parameter not specified

While converting from non-rac to rac, I'm facing a problem with mounting.

Pfile :

testrac.__db_cache_size=503316480

testrac.__java_pool_size=16777216

testrac.__large_pool_size=33554432

testrac.__oracle_base='/RACTEST'#ORACLE_BASE set from environment

testrac.__pga_aggregate_target=520093696

testrac.__sga_target=754974720

testrac.__shared_io_pool_size=0

testrac.__shared_pool_size=184549376

testrac.__streams_pool_size=0

*.audit_file_dest='/oracle/RACDB/admin/testrac/adump'

*.audit_trail='db'

*.compatible='11.2.0.4'

*.control_files='+DATA/testrac/controlfile/current.256.877778671'

*.db_block_size=8192

*.db_domain=''

*.db_unique_name='testrac'

*.db_name='testrac1'

*.db_recovery_file_dest='/RACTEST/fast_recovery_area'