Remember that the C is usually Tz in Russian and Latvian. .Remember also that the person transcribing the records may put an S or a Z. Using the Ts or Tz you can find a number of records on Jewishgen. eg Tselevich Tselevitz Tselevets Tsilevich.
I mentioned to you that Karsava was in Latgale which was in Vitebsk Gubernia until 1919. After 1919 Vitebsk gubernia ceased to exist. Karsava went back to Latvia and part of Vitebsk Gubernia was in Belarus. You may have relatives from Belarus and as I said some of the records may be in the Minsk Archives.
Searching Jewishgen there are many Tzilevich from Rezekne.You need to be really openminded about spelling.
I am busy transcribing Internal passport handed in to the Riga Police, These 2 names are in the Rezekne records. Sadly the Passports are not in the records merely a document.
Ilya was born 1899 and had 2 sons Mendel 1923 and Peisach 1925.
Co-director Latvia Research Division.