If you ask me which one to choose I would say choosing Textile from IIT Delhi is a better option than opting for Electrical in IIT Mandi.
You will be glad to know that I interact frequently with fresh IIT graduates and thus am the right person to answer this question. Both EE in IIT Mandi and Textile Engineering at IIT Delhi are highly reputable programs. Electrical Engineering is a broad field that covers many different areas, including power systems, control systems, electronics, and communications. whereas Textile Engineering is more specialized and focuses specifically on the design, development, and manufacturing of textiles and fabrics.
Most IITs provide a base level of quality when it comes to the quality of education imparted. On interacting with students from IIT Mandi, Ropar, Jodhpur, Patna, etc I have formed the opinion that opening more IITs is a good idea as it raises the base quality level of engineering institutes around India. There is no dilution in the brand name of old IITs unlike what people usually believe.
In my opinion, it’s more important to focus on what is being taught than where it’s being taught. A textile engineer works very very hard and has to opt for minor electives to gain expertise in technology and has to complete several internships too. Then too, many top firms restrict themselves to engineers from top departments. So the same company might hire electrical engineers from IIT Delhi and IIT Mandi but will not consider IIT Delhi textile engineers to be of the same level as the latter.