Probhat is currently most popular keyboard layout for writing Bengali in linux. Please add it in by default.
These are the codes I added to my configuration file to define my own Probhat layout:
;; Probhat Input Method
(quail-define-package
"probhat" "Bengali-probhat" "probhat" t
"Porbhat for Bangla" nil t nil nil nil nil nil nil nil nil t)
(quail-define-rules
("!" ?!)
("1" ?১)
("@" ?@)
("2" ?২)
("#" ?#)
("3" ?৩)
("$" ?৳)
("4" ?৪)
("%" ?%)
("5" ?৫)
("^" ?^)
("6" ?৬)
("&" ?ঞ)
("7" ?৭)
("*" "ৎ")
("8" ?৮)
("(" ?()
("9" ?৯)
(")" ?))
("0" ?০)
("_" ?_)
("-" ?-)
("+" ?+)
("=" ?=)
("Q" ?ধ)
("q" ?দ)
("W" ?ঊ)
("w" ?ূ)
("E" ?ঈ)
("e" ?ী)
("R" ?ড়)
("r" ?র)
("T" ?ঠ)
("t" ?ট)
("Y" ?ঐ)
("y" ?এ)
("U" ?উ)
("u" ?ু)
("I" ?ই)
("i" ?ি)
("O" ?ঔ)
("o" ?ও)
("P" ?ফ)
("p" ?প)
("{" ?ৈ)
("[" ?ে)
("}" ?ৌ)
("]" ?ো)
("A" ?অ)
("a" ?া)
("S" ?ষ)
("s" ?স)
("D" ?ঢ)
("d" ?ড)
("F" ?থ)
("f" ?ত)
("G" ?ঘ)
("g" ?গ)
("H" ?ঃ)
("h" ?হ)
("J" ?ঝ)
("j" ?জ)
("K" ?খ)
("k" ?ক)
("L" ?ং)
("l" ?ল)
(":" ?:)
(";" ?;)
(""" ?")
("'" ?')
("|" ?॥)
("" ?)
("~" ?~)
("`" ?)
("Z" ?য)
("z" ?য়)
("X" ?ঢ়)
("x" ?শ)
("C" ?ছ)
("c" ?চ)
("V" ?ঋ)
("v" ?আ)
("B" ?ভ)
("b" ?ব)
("N" ?ণ)
("n" ?ন)
("M" ?ঙ)
("m" ?ম)
("<" ?ৃ)
("," ?,)
(">" ?ঁ)
("." ?।)
("?" ??)
("/" ?্))