When is Yehalelu to be recited on Mincha of Shabbos?
In general, the verse of Yehalelu is recited by the Chazan when the Sefer Torah is being brought to the Aron. However, according to the Chabad custom to begin the Kaddish towards the end of the Gelila, this forms a problem regarding when it is to be said. On the one hand, one may not speak in middle of Kaddish, and must pay attention to the words of the Kaddish said by the Chazan. On the other hand, one is not to make an interval between Kaddish and Shemoneh Esrei [at all] even with the recital of a single Pasuk, and therefore, Yehalelu is not to be recited after the Kaddish, before Shemoneh Esrei, but rather is to be said before the Kaddish. Practically, according to the Rebbe’s directives, Yehalelu is to be recited after Gelila, while the Sefer Torah is being returned to the Aron, in the midst of the Kaddish, and not between the Kaaddish and Shemoneh Esrei. [Perhaps, it is best to recite it after answering Amen Yihei Shmei Raba, prior to the Chazan continuing the Kaddish. While the Chazan who says the Half Kaddish should say it to himself before he begins the half Kaddish.] Some however write the Rebbe was accustomed to recite Yehalelu only after the Kaddish was completed by the Chazan, prior to beginning Shemoneh Esrei.
 Siddur Admur “On Monday’s and Thursday’s one enters the Sefer Torah to the Heichal and the Chazan says Yehalelu.”
When to say Yehalelu-before or during the return of the Torah? Some write that Yehalelu and Hodu is recited prior to bringing the Sefer Torah back to the Aron, and after it is said, it is brought to the Aron. [Machzor Vitri ibid; Implication of Mateh Moshe ibid; Shaareiy Efraim 10/41] However from Siddur Admur ibid it is implied that it is said while it is being brought to the Aron. Vetzaruch Iyun!
 See Ketzos Hashulchan 91 footnote 4 “If Kaddish is said while the Sefer Torah is brought to the heychal and people come to kiss it and say Yehalelu it will cause confusion and people will not listen to the Kaddish.”
 Admur 292/4; M”A 292/2
 Yad Efraim 292 on M”A ibid; Ketzos Hashulchan 91 Footnote 4
 Igros Kodesh 313; Sefer Haminhagim p. 66 [English] [printed in Shulchan Menachem 2/109]
 Siddur Harav Raskin p. 320; Likkut of Rav Shimon Yakobavitch, printed in Hiskashrus 212/25; Rabbi Groner in correspondence that the Rebbe said Yehalelu after the Kaddish