Copy paste and save as .ahk file :

#NoEnv ; Recommended for performance and compatibility with future AutoHotkey releases.
; #Warn ; Enable warnings to assist with detecting common errors.
SendMode Input ; Recommended for new scripts due to its superior speed and reliability.
SetWorkingDir %A_ScriptDir% ; Ensures a consistent starting directory.

^Down:: ; Ctrl+down key to activate.

Loop, 20 ; Number of raffles it will enter.
{

Loop, 17 { ; Number of Tab you need to press to Enter the raffle (this will change if OP added a link in the raffle description or a poll).
Send, {TAB}
Sleep 10
}
Send, {enter}

Sleep 6600 ; Waiting time in ms, depends on your browser speed.

Loop, 14 ; Number of "Tab" you need to press to click the link to the next raffle.
{
Send, {TAB}
Sleep 11
}
Send, {enter}

Sleep 2000 ; Waiting time in ms, depends on your browser speed.

Send, {Ctrl down} ; Auto-closing the previous raffle, depends on your browser. On Firefox it's ctrl+tab and ctrl+w.
Sleep 10
Send, {tab}
Sleep 500
Send, {w}
Sleep, 200
Send, {Ctrl up}
Sleep, 1800
}
Return