Records not getting replicate from Mysql 5.5.32 to MySQL 5.6

1. I have a MySQL 5.5.32 server (community edition) on one Linux server which is master.
2. I have a MySQL 5.6 server (community edition) on another Linux server which is slave. I have installed various instances of MySQL on this machine with having different ports. Various instances for replicating different sources
3. Statement based Replication has been set up between these two servers.

If i do show slave status\G; I don't see any errors here and replication is working , but when i see count of records, it is not increasing at slave end.

Also, slave is continuously receiving relay log files, but I feel relay logs are not being written by the slave I/O thread.

I see below error in log file :

[ERROR] Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)

[Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.019362' at position 488205064 

[Warning] Slave I/O: Notifying master by SET @master_binlog_checksum= @@global.binlog_checksum failed with error: Unknown system variable 'binlog_checksum', Error_code: 1193

[Warning] Slave I/O: Unknown system variable 'SERVER_UUID' on master. A probable cause is that the variable is not supported on the master (version: 5.5.32-log), even though it is on the slave (version: 5.6.26-log), Error_code: 1193

Also I have made changes to

set global binlog_checksum='NONE';

but still condition is same.

Below is slave's my.cnf file

    [mysqld]
    server-id=24
    log-bin=mysql-bin
    binlog_format=ROW
    relay_log=relay-log
    replicate-do-table=db.tb
    datadir=/var/lib/mysql/
    socket=/var/lib/mysql/mysql.sock
    user=mysql
    skip-name-resolve
    log_bin=/var/lib/mysql/logs.index
    log_bin_trust_function_creators=1
    old_passwords=0
    bind_address=127.0.0.1
    max_connections=10
    symbolic-links=0
    max_allowed_packet=110M
    query_cache_size=512M
    query_cache_limit=256M
    wait_timeout=600
    key_buffer_size=512M
    sort_buffer_size=256K
    innodb_buffer_pool_size=1024M
    flush_time=620
    # The TCP/IP Port the MySQL Server will listen on
    port=3306
    symbolic-links=0
    binlog_checksum=NONE
    slave_sql_verify_checksum=OFF

    [mysqld_safe]
    log-error=/var/log/mysqld.log
    pid-file=/var/run/mysqld/mysqld.pid

Please help, what is happening around . Is this because of different versions? But MySQL doc says, replication between two different version is possible.

Below is Master my.cnf

     [client]
     port       = 3306
     socket     = /var/lib/mysql/mysql.sock

     [mysqld]
     performance_schema
     port       = 3306
     socket     = /var/lib/mysql/mysql.sock
     log = /var/log/mysqld.log
     log_warnings=2
     log-error = /var/log/mysqld.error.log
     long_query_time=1
     log-slow-queries=/var/log/mysql-slow-queries.log

     slow-query-log = 1
     slow-query-log-file = /var/log/mysql-slow.log
     log_bin_trust_function_creators = 1
     skip-name-resolve
     skip-external-locking
     innodb_file_per_table=1
     expire-logs-days=30
     key_buffer_size = 4096M
     key_buffer = 1024M
     max_allowed_packet = 1G
     low_priority_updates=1
     concurrent_insert=ALWAYS
     lower_case_table_name = 1
     table_open_cache = 3000
     table_cache = 5000
     sort_buffer_size = 50M
     read_buffer_size = 15M
     read_rnd_buffer_size = 20M
     join_buffer_size = 100M
     myisam_sort_buffer_size = 512M
     thread_stack = 12M
     thread_cache_size = 20
     query_cache_size = 512M
     query_cache_type = 1
     query_cache_limit = 512M
     max_connections = 300
     tmp_table_size = 256M
     max_heap_table_size = 512M
     innodb_buffer_pool_size = 40G
     binlog_cache_size = 5M
     innodb_flush_method = O_DIRECT
     innodb_additional_mem_pool_size = 20M
     innodb_log_buffer_size = 10M

     # Try number of CPU's*2 for thread_concurrency
     thread_concurrency = 8
     collation_server=utf8_general_ci
     character_set_server=utf8
     init_connect="SET NAMES 'utf8'"


     # binary logging is required for replication
     log-bin=mysql-bin

     server-id  = 1
     binlog-do-db=#database name1
     slave-skip-error=1062
     relay-log = /var/lib/mysql/mysql-relay-bin
     relay-log-index = /var/lib/mysql/mysql-relay-bin.index
     master-info-file = /var/lib/mysql/mysql-master.info
     relay-log-info-file = /var/lib/mysql/mysql-relay-log.info
     log-bin=/var/lib/mysql/mysql-bin

     symbolic-links=0


     innodb_additional_mem_pool_size = 50M
     # Set .._log_file_size to 25 % of buffer pool size
     innodb_log_file_size = 512M
     innodb_log_buffer_size = 8M
     innodb_flush_log_at_trx_commit = 1
     innodb_lock_wait_timeout = 100

     [mysqldump]
     quick
     max_allowed_packet = 16M

     [mysql]
     no-auto-rehash

        [myisamchk]
     key_buffer_size = 256M
     sort_buffer_size = 256M
     read_buffer = 2M
     write_buffer = 2M

     [mysqlhotcopy]
     interactive-timeout

UPDATE : I just noticed that relay log files are not getting purged on their own and lot of relay log files has been keep on generating.