[Snake.]

If someone retry in 20 seconds, they will be automatically transfered to CT team. Thanks in advance.

[DJEarthQuake]

#include amxmodx
//If client retries in 20 sec auto CT.
#define SNAKE 5000
#define disconnected disconnect

public plugin_init()
{
    register_plugin("Force CT on 20s retry","A",".sρiηX҉.");
}

public client_putinserver(id)
{
    set_user_info(id,"_vgui_menus", "0")

    if(task_exists(id+SNAKE))
        change_task(id+SNAKE, 0.3) &&
        set_msg_block( get_user_msgid( "MOTD" ), BLOCK_SET );
    else
        CS_OnBuyAttempt(id)
}

public set_team_ct(TaskID)
{
    new id = TaskID-SNAKE
    set_user_info(id,"_vgui_menus", "0")

    client_cmd(id,"jointeam 2");
}

public CS_OnBuyAttempt(id){ set_user_info(id,"_vgui_menus", "0");}

public client_disconnected(id)
{
    set_task(20.0,"set_team_ct", id+SNAKE);
}

[Relaxing]

Try if this kicks you from reconnecting and if so change it to set the team.

#include <amxmodx>
#define RETRY 20

new Trie:trie;
new steamid[MAX_PLAYERS+1][32];

public plugin_init(){
    trie = TrieCreate();
}

public client_authorized(id){
    get_user_authid(id, steamid[id], charsmax(steamid[]));
    _do(steamid[id], id);
}

public client_disconnected(id){
    TrieSetCell(trie, steamid[id], get_systime());
    set_task(float(RETRY), "delete_entry", _, steamid[id], charsmax(steamid[]))
}

public delete_entry(_steamid[32]){
    _do(_steamid);
}

stock _do(input[], id=0){
    new _time, _systime = get_systime();
    
    if (TrieGetCell(trie, input, _time)){
        if (id && _systime - _time <= RETRY)
                server_cmd("kick #%d", get_user_userid(id));
        else TrieDeleteKey(trie, input);
    }
}

[alferd]

#include <amxmod>

#pragma semicolon 1

const TASKID_Autojoin = 583079;

new const FIRST_JOIN_MSG[] =        "#Team_Select";
new const FIRST_JOIN_MSG_SPEC[] =   "#Team_Select_Spect";
new const INGAME_JOIN_MSG[] =      "#IG_Team_Select";
new const INGAME_JOIN_MSG_SPEC[] =  "#IG_Team_Select_Spect";
const iMaxLen = sizeof( INGAME_JOIN_MSG_SPEC );

public plugin_init() {
    register_plugin( "Auto CT Join", "1.0", "Exolent" );
    
    register_message( get_user_msgid("ShowMenu"), "msgShowMenu" );
    register_message( get_user_msgid("VGUIMenu"), "msgVGUIMenu" );
    
    // I know this is gay but ffs sometimes it doesnt blocked...
    register_clcmd( "chooseteam", "cmdBlock" );
}

public plugin_cfg() {
    set_cvar_num( "mp_limitteams", 32 );
    set_cvar_num( "mp_autoteambalance", 0 );
    set_cvar_num( "sv_restart", 1 );
}

public cmdBlock( id )
    return PLUGIN_HANDLED;

public client_disconnect( id )
    remove_task( id + TASKID_Autojoin );

public msgShowMenu( iMsgid, iDest, id ) {
    static sMenuCode[iMaxLen];
    get_msg_arg_string(4, sMenuCode, sizeof(sMenuCode) - 1);
    
    if( equal(sMenuCode, FIRST_JOIN_MSG) || equal(sMenuCode, FIRST_JOIN_MSG_SPEC) ) {
        if( should_autojoin(id) ) {
            set_autojoin_task(id, iMsgid);
            return PLUGIN_HANDLED;
        }
    }
    else if( equal(sMenuCode, INGAME_JOIN_MSG) || equal(sMenuCode, INGAME_JOIN_MSG_SPEC) )
        return PLUGIN_HANDLED;
    
    return PLUGIN_CONTINUE;
}

public msgVGUIMenu( iMsgid, iDest, id ) {
    if( get_msg_arg_int(1) != 2 )
        return PLUGIN_CONTINUE;
    
    if( should_autojoin(id) ) {
        set_autojoin_task(id, iMsgid);
        return PLUGIN_HANDLED;
    }
    
    return PLUGIN_CONTINUE;
}

public task_Autojoin( iParam[], id )
    handle_join( id - TASKID_Autojoin, iParam[0] );

handle_join( id, iMsgid ) {
    new iMsgBlock = get_msg_block( iMsgid );
    set_msg_block( iMsgid, BLOCK_SET );
    
    engclient_cmd( id, "jointeam", "2" );
    
    new iClass[2];
    iClass[0] = random_num( '1', '4' );
    engclient_cmd( id, "joinclass", iClass );
    
    set_msg_block( iMsgid, iMsgBlock );
}

set_autojoin_task( id, iMsgid ) {
    new iParam[1];
    iParam[0] = iMsgid;
    set_task( 0.1, "task_Autojoin", id + TASKID_Autojoin, iParam, sizeof(iParam) );
}

should_autojoin( id )
    return ( is_user_connected(id) && get_user_team(id) != 2 && !task_exists(id + TASKID_Autojoin) );