HOW we Check quota unlimited on particular user?

If the bytes=-1 in DBA_TS_QUOTAS view it means tablespace quota is unlimited on that user.

SQL> desc dba_Ts_quotas;
Name Null?
Type ----------------------------------------- -------- ---------------------------- TABLESPACE_NAME NOT NULL VARCHAr2(30)
USERNAME NOT NULL VARCHAR2(30)
BYTES NUMBER
MAX_BYTES NUMBER
BLOCKS NOT NULL NUMBER
MAX_BLOCKS NUMBER
SQL> select username,max_bytes from dba_Ts_quotas;
USERNAME MAX_BYTES
------------------------ ------------------------
TEMP -1